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1. Magnesium and magnesium alloy dissolution by high intensity focused ultrasound: erosion/cavitation vs. Wave propagation

Author

Noura Sleiman, Rachel Pflieger, Loïc Hallez, Sergey I. Nikitenko, and Jean-Yves Hihn

Subjects
Magnesium, Magnesium alloys, High-intensity focused ultrasound, Cavitation, Acoustic streaming, Dissolution, Chemistry, QD1-999, Acoustics. Sound, QC221-246
Abstract

The dissolution of metals, influenced by mechanical and chemical factors, plays a crucial role in various applications. Ultrasonic irradiation has been explored for its ability to enhance dissolution rates and modify surface characteristics. In this study, we investigate the dissolution of magnesium (Mg) and magnesium alloys under high-intensity focused ultrasound (HIFU) conditions with frequency sweeping (wobbling). Our findings reveal distinct effects of cavitation and acoustic streaming on the dissolution process. For pure magnesium, ultrasonic treatment significantly increases dissolution rates compared to silent conditions. Negative frequency sweeps result in the highest dissolution rates, linked to increased cavitation activity, while positive sweeps reduce dissolution rates but maintain acoustic streaming effects. The removal of surface oxides is accelerated in all sonication conditions. Macro- and micro-roughness patterns on the surface correspond to the wobbling frequency range, with wavelengths matching the average ultrasonic frequency. However, dissolution is not uniform across the sample, and preferential attack occurs at the focal point during negative frequency sweeps. In contrast, magnesium alloys exhibit lower dissolution rates than pure Mg. The alloy's mechanical properties make it less susceptible to cavitation erosion but more sensitive to acoustic streaming-induced dissolution. Grain boundaries are preferentially attacked, revealing differences between ductile pure Mg and the harder, more cavitation-resistant, alloy. This study highlights the complex interplay between cavitation and acoustic streaming in the dissolution of magnesium and its alloys under HIFU conditions, shedding light on the limits and potential applications of this technique, particularly in microstructure analysis.

Published
2024
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2. Sonoluminescence emission spectra of a 3.6 MHz HIFU in sweeping mode

Author

Noura Sleiman, Loïc Hallez, Rachel Pflieger, Sergey I. Nikitenko, and Jean-Yves Hihn

Subjects
HIFU, Frequency sweep, Cavitation, Sonoluminescence, Emission spectra, Chemistry, QD1-999, Acoustics. Sound, QC221-246
Abstract

Use of sweeping mode with a 3.6 MHz High Intensity Focused Ultrasound (HIFU) allows cavitation activity to be controlled. This is especially true in the pre-focal zone where the high concentration of bubbles acts as an acoustic reflector and quenches cavitation above this area. Previous studies attributed the enhancement of cavitation activity under negative sweep to the activation of more bubble nuclei, requiring deeper investigations. After mapping this activity with SCL measurements, cavitation noise spectra were recorded. The behavior of the acoustic broadband noise follows the sonochemical one i.e., showing the same attenuation (positive scan) or intensification (negative scan) of cavitational activity. In 1 M NaCl 3.7 mM 2-propanol solution saturated by a mixture of Ar-15.5%O2-2.2%N2, intensities of SL spectra are high enough to allow detection of several molecular emissions (OH, NH, C2, Na) under negative frequency sweeps. This is the first report of molecular emissions at such high frequency. Their intensities are low, and they are very broad, following the trend obtained at fixed frequency up to 1 MHz. Under optimized conditions, CN emission chosen as a spectroscopic probe is strong enough to be simulated, which is reported for the first time at such high frequency. The resulting characteristics of the plasma do not show any spectral difference, so bubble nature is the same in the pre-and post-focal zone under different sweeping parameters. Consequently, SL and SCL intensification was not related to a change in plasma nature inside the bubbles but to the number of cavitation bubbles.

Published
2022
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3. Impact of bubble coalescence in the determination of bubble sizes using a pulsed US technique: Part 2 – Effect of the nature of saturating gas

Author

Rachel Pflieger, Geoffrey Audiger, Sergey I. Nikitenko, and Muthupandian Ashokkumar

Subjects
Bubble size, Pulsed ultrasound, Coalescence, Sonoluminescence, He, Xe, Chemistry, QD1-999, Acoustics. Sound, QC221-246
Abstract

Knowledge on cavitation bubble size distribution, ambient radius of bubbles is of interest for many applications that include therapeutic and diagnostic medicine. It however becomes a hard quest when increasing the ultrasonic frequency, when direct observation of bubble dynamics is no longer possible. An indirect method based on the estimation of the bubble dissolution time under pulsed ultrasound (362 kHz) is used here under optimized conditions to derive ambient radii of cavitation bubbles in water saturated with He, Ar, Xe, O2, N2 and air: 3.0 µm for Ar, 1.2 µm for He, 3.1 µm for Xe, 2.8 µm for O2, around 1 µm for N2 and air. If the pulse on-time is increased, bubble coalescence occurs, the extent of which is rather limited for Ar but extremely high for He or N2.

Published
2021
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4. Impact of bubble coalescence in the determination of bubble sizes using a pulsed US technique: Part 1 – Argon bubbles in water

Author

Rachel Pflieger, Julia Bertolo, Léa Gravier, Sergey I. Nikitenko, and Muthupandian Ashokkumar

Subjects
Bubble size, Pulsed ultrasound, Coalescence, SDS, Sonoluminescence, Ar, Chemistry, QD1-999, Acoustics. Sound, QC221-246
Abstract

A powerful experimental approach to measure the size distribution of bubbles active in sonoluminescence and/or sonochemistry is a technique based on pulsed ultrasound and sonoluminescence emission. While it is an accepted technique, it is still lacking an understanding of the effect of various experimental parameters, including the duration of the pulse on-time, the nature of the dissolved gas, the presence of a gas flow rate, etc. The present work, focusing on Ar-saturated water sonicated at 362 kHz, shows that increasing the pulse on-time leads to the measurement of coalesced bubbles. Reducing the on-time to a minimum and/or adding sodium dodecyl sulfate to water allows to reducing coalescence so that natural active cavitation bubble sizes can be measured. A radius of 2.9–3.0 µm is obtained in Ar-saturated water at 362 kHz. The effects of acoustic power and possible formation of a standing-wave on coalescence and measured bubble sizes are discussed.

Published
2021
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5. Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles

Author

Sara El Hakim, Tony Chave, and Sergey I. Nikitenko

Subjects
Sonochemistry, Sonocatalysis, EDTA, Titanium nanoparticles, Heterogeneous catalysis, Chemistry, QD1-999, Acoustics. Sound, QC221-246
Abstract

The sonocatalytic degradation of EDTA (C0 = 5 10−3 M) in aqueous solutions was studied under 345 kHz (Pac = 0.25 W mL−1) ultrasound at 22–51 °C, Ar/20%O2, Ar or air, and in the presence of metallic titanium (Ti0) or core-shell Ti@TiO2 nanoparticles (NPs). Ti@TiO2 NPs have been obtained using simultaneous action of hydrothermal conditions (100–214 °C, autogenic pressure P = 1.0–19.0 bar) and 20 kHz ultrasound, called sonohydrothermal (SHT) treatment, on Ti0 NPs in pure water. Ti0 is composed of quasi-spherical particles (30–150 nm) of metallic titanium coated with a metastable titanium suboxide Ti3O. SHT treatment at 150–214 °C leads to the oxidation of Ti3O and partial oxidation of Ti0 and formation of nanocrystalline shell (10–20 nm) composed of TiO2 anatase. It was found that Ti0 NPs do not exhibit catalytic activity in the absence of ultrasound. Moreover, Ti0 NPs remain inactive under ultrasound in the absence of oxygen. However, significant acceleration of EDTA degradation was achieved during sonication in the presence of Ti0 NPs and Ar/20%O2 gas mixture. Coating of Ti0 with TiO2 nanocrystalline shell reduces sonocatalytic activity. Pristine TiO2 anatase nanoparticles do not show a sonocatalytic activity in studied system. Suggested mechanism of EDTA sonocatalytic degradation involves two reaction pathways: (i) sonochemical oxidation of EDTA by OH·/HO2· radicals in solution and (ii) EDTA oxidation at the surface of Ti0 NPs in the presence of oxygen activated by cavitation event. Ultrasonic activation most probably occurs due to the local heating of Ti0/O2 species at cavitation bubble/solution interface.

Published
2021
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6. Modification of Olive Leaves’ Surface by Ultrasound Cavitation. Correlation with Polyphenol Extraction Enhancement

Author

Natacha Rombaut, Tony Chave, Sergey I. Nikitenko, Mohamed EI Maâtaoui, Anne Sylvie Fabiano-Tixier, and Farid Chemat

Subjects
olive leaf, microscopy, polyphenol, ultrasound, mechanism, food processing, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract

We investigated the impact of ultrasound at 20 kHz on olive leaves to understand how acoustic cavitation could increase polyphenol extraction. Application of ultrasound to whole leaf from 5 to 60 min enabled us to increase extraction from 6.96 to 48.75 µg eq. oleuropein/mL of extract. These results were correlated with Environmental Scanning Electron Microscopy, allowing for leaf surface observation and optical microscopy of treated leaf cross sections to understand histochemical modifications. Our observations suggest that the effectiveness of ultrasound applied to extraction is highly dependent on plant structure and on how this material will react when subjected to acoustic cavitation. Ultrasound seems to impact the leaves by two mechanisms: cuticle erosion, and fragmentation of olive leaf surface protrusions (hairs), which are both polyphenol-rich structures.

Published
2020
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7. Ultrasonically controlled synthesis of UO2+xcolloidal nanoparticles

Author

Manon Cot-Auriol, Matthieu Virot, Thomas Dumas, Olivier Diat, Xavier Le Goff, Philippe Moisy, and Sergey I. Nikitenko

Subjects
Inorganic Chemistry
Abstract

Sonochemistry was used for the preparation of uranium oxide nanoparticles. In comparison to classical hydrolysis approach, larger, better defined and more crystalline UO2+xnanoparticles were observed under ultrasound.

Published
2023
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9. Influence of Butanol Isomerization on Photothermal Hydrogen Production over Ti@TiO2 Core-Shell Nanoparticles

Author

Sara El Hakim, Mathéo Bathias, Tony Chave, and Sergey I. Nikitenko

Subjects
photocatalysis, hydrogen production, butanol, isomers, photothermal effect, titanium, Physical and Theoretical Chemistry, Catalysis, General Environmental Science
Abstract

In this work, we reported for the first time the effect of butanol isomerization on the photothermal production of hydrogen in the presence of a noble, metal-free Ti@TiO2 core-shell photocatalyst. The experiments were performed in aqueous solutions of 1-BuOH, 2-BuOH, and t-BuOH under Xe lamp irradiation (vis/NIR: 8.4 W, UV: 0.6 W) at 35–69 °C. The increase in temperature significantly enhanced H2 formation, indicating a strong photothermal effect in the studied systems. However, in dark conditions, H2 emission was not observed even at elevated temperatures, which clearly points out the photonic origin of H2 photothermal formation. The rate of H2 production followed the order of 1-BuOH >> 2-BuOH > t-BuOH in the entire range of studied temperatures. In the systems with 1-BuOH and 2-BuOH, hydrogen was the only gaseous product measured online in the outlet carrier argon using mass spectrometry. By contrast, a mixture of H2, CH4, and C2H6 was detected for t-BuOH, indicating a C–C bond scission with this isomer during photocatalytic degradation. The apparent activation energies, Ea, with 1-BuOH/2-BuOH isomers (20–21 kJ·mol−1) was found to be larger than for t-BuOH (13 kJ·mol−1). The significant difference in thermal response for 1-BuOH/2-BuOH and t-BuOH isomers was ascribed to the difference in the photocatalytic mechanisms of these species. The photothermal effect with 1-BuOH/2-BuOH isomers can be explained by the thermally induced transfer of photogenerated, shallowly trapped electron holes to highly reactive free holes at the surface of TiO2 and the further hole-mediated cleavage of the O-H bond. In the system with t-BuOH, another mechanism could also contribute to the overall process through hydrogen abstraction from the C–H bond by an intermediate •OH radical, leading to CH3• group ejection. Formation of •OH radicals during light irradiation of Ti@TiO2 nanoparticle suspension in water has been confirmed using terephthalate dosimetry. This analysis also revealed a positive temperature response of •OH radical formation.

Published
2022
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10. First observation of [Pu6(OH)4O4 ]12+ cluster during the hydrolytic formation of PuO2 nanoparticles using H/D kinetic isotope effect

Author

Manon Cot-Auriol, Matthieu Virot, Thomas Dumas, Olivier Diat, Denis Menut, Philippe Moisy, Sergey I. Nikitenko, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Institut des Sciences et technologies pour une Economie Circulaire des énergies bas carbone (ISEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ions aux Interfaces Actives (L2IA), Synchrotron SOLEIL (SSOLEIL), and Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials Chemistry, Metals and Alloys, Ceramics and Composites, General Chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, [CHIM.RADIO]Chemical Sciences/Radiochemistry, Catalysis, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Abstract

New insights are provided about the formation mechanism of PuO2 nanoparticles (NPs) by investigating an unprecedented kinetic isotope effect observed during their hydrolytic synthesis in H2O or D2O media.

Published
2022
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11. Synthesis and multi-scale properties of PuO2 nanoparticles: recent advances and open questions

Author

Matthieu Virot, Thomas Dumas, Manon Cot-Auriol, Philippe Moisy, Sergey I. Nikitenko, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Institut des Sciences et technologies pour une Economie Circulaire des énergies bas carbone (ISEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
General Engineering, General Materials Science, Bioengineering, General Chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, [CHIM.RADIO]Chemical Sciences/Radiochemistry, Atomic and Molecular Physics, and Optics
Abstract

The review focuses on the recent relevant progresses observed about PuO2 nanoparticle syntheses and characterizations including the recently deciphered electronic, structural and physico-chemical properties.

Published
2022
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12. Deciphering the reaction mechanisms of photothermal hydrogen production using H/D kinetic isotope effect

Author

Sara El Hakim, Tony Chave, Sergey I. Nikitenko, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Sonochimie dans les Fluides Complexes (LSFC), and Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, Catalysis
Abstract

International audience; H/D kinetic isotope effect has been employed to study the mechanism of the thermally assisted photocatalytic hydrogen production over noble metal-free Ti@TiO$_2$ core–shell nanoparticles. We have found that the observed large H/D isotope separation factor (αH = 11.3 ± 1.7–6.2 ± 0.9) is due to the electron hole-mediated cleavage of OH bond. It was concluded that strong H/D isotopic selectivity is associated with significant photothermal effect.

Published
2022
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13. Sonochemistry of actinides: from ions to nanoparticles and beyond

Author

Sergey I. Nikitenko, Matthieu Virot, Philippe Moisy, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Institut des Sciences et technologies pour une Economie Circulaire des énergies bas carbone (ISEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
[CHIM]Chemical Sciences, Physical and Theoretical Chemistry, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract

Sonochemistry studies chemical and physical effects in liquids submitted to power ultrasound. These effects arise not from a direct interaction of molecules with sound waves, but rather from the acoustic cavitation: the nucleation, growth, and implosive collapse of microbubbles in liquids submitted to power ultrasound. The violent implosion of bubbles leads to the formation of chemically reactive species. In principle, each cavitation bubble can be considered as a microreactor initiating chemical reactions at mild conditions. In addition, microjets and shock waves accompanied bubble collapse produce fragmentation, dispersion and erosion of solid surfaces or particles. Microbubbles oscillating in liquids also enable nucleation and precipitation of nanosized actinide compounds with specific morphology. This review focuses on the versatile sonochemical processes with actinide ions and particles in homogenous solutions and heterogenous systems. The redox reactions in aqueous solutions, dissolution or precipitation of refractory solids, synthesis of actinide nanoparticles, and ultrasonically driving decontamination are considered. The guideline for further research is also discussed.

Published
2022
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14. Simultaneous H/D and $^{13}$C/$^{12}$C anomalous kinetic isotope effects during the sonolysis of water in the presence of carbon monoxide

Author

Sergey I. Nikitenko, Tony Chave, Matthieu Virot, Rachel Pflieger, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), and Université de Montpellier (UM)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], General Materials Science, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry
Abstract

International audience; Splitting of water molecules driven by ultrasound plays a central role in sonochemistry. While studies of sonoluminescence revealed the formation of a plasma inside the cavitation bubble, much less is known about the contribution of plasma chemical processes to the sonochemical mechanisms. Herein, we report for the first time sonochemical processes in water saturated with pure CO. The presence of CO causes a large increase in the H/D kinetic isotope effect (KIE) to $\alpha_H$ = 14.6 ± 1.8 in a 10% H$_2$O/D$_2$O mixture under 20 kHz ultrasound.The anomalous H/D KIE is attributed to electron quantum tunneling in the plasma produced by cavitation. In addition, CO$_2$ formed simultaneously with hydrogen during the sonochemical process is enriched with the $^{13C}$C isotope, which indicates a VV pumping mechanism typical for non-equilibrium plasma. Both observed KIEs unambiguously point to the contribution of quantum effects in sonochemical mechanisms.

Published
2022
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15. Simultaneous H/D and

Author

Sergey I, Nikitenko, Tony, Chave, Matthieu, Virot, and Rachel, Pflieger

Abstract

Splitting of water molecules driven by ultrasound plays a central role in sonochemistry. While studies of sonoluminescence revealed the formation of a plasma inside the cavitation bubble, much less is known about the contribution of plasma chemical processes to the sonochemical mechanisms. Herein, we report for the first time sonochemical processes in water saturated with pure CO. The presence of CO causes a large increase in the H/D kinetic isotope effect (KIE) to α

Published
2021

17. INFLUENCE OF THE WORLD INNOVATION PROJECT 'INDUSTRY 4.0' ON THE DEVELOPMENT OF THE RUSSIAN ENERGY SECTOR

Author

Irina Filimonova, E V Goosen, Sergey I. Nikitenko, Olga Kavkaeva, and E O Pakhomova

Subjects
Industry 4.0, business.industry, Materials Science (miscellaneous), Fossil fuel, Industrial and Manufacturing Engineering, Value theory, Upgrade, Development (topology), Petroleum industry, Production (economics), Business and International Management, business, Citation, Industrial organization
Abstract

The aim of the article is to attempt to identify the profound changes taking place in the global and Russian energy sectors. One of the key drivers of the new development paradigm is the active implementation of the Industry 4.0 project elements in the fuel and energy complex, which is comprehensive and relies on digital technologies. The features of the global innovation project “Industry 4.0” and, in particular, the digitalization of the oil and gas sector were studied. The possibility of transition of the Russian energy complex to a new development paradigm is also analyzed, it consists in the implementation of elements of the Industry 4.0 project. The problems of the Russian energy sector on the transition to a new development model, which are associated with the features of its production, market and institutional structures, are identified. The theory of value chains in the fuel and energy complex and its upgrade is separately studied. The main niche in the Russian energy sector is highlighted, in which the development of the Industry 4.0 paradigm is possible. Nore: The paper is an extended version of the article presented at the conference SGEM Vienna Green 2019 Conference (9-11 December, 2019), Austria. Reference citation: https://doi.org/10.5593/sgem2019V/1.4The title, abstract was changed in the article / The degree of knowledge of the chains added in the fuel and energy complex was also considered — 3- 4 pp.

Published
2020
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18. Relevance of formation conditions to the size, morphology and local structure of intrinsic plutonium colloids

Author

Olivier Diat, Laurent Venault, Sandrine Dourdain, Thomas Dumas, Matthieu Virot, Philippe Moisy, Denis Menut, Cyril Micheau, Pier Lorenzo Solari, Sergey I. Nikitenko, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Tri ionique par les Systèmes Moléculaires auto-assemblés (LTSM), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Ions aux Interfaces Actives (L2IA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'Energie Atomique, Saclay (CEA)

Subjects
X-ray absorption spectroscopy, Materials science, Absorption spectroscopy, Small-angle X-ray scattering, Scattering, Materials Science (miscellaneous), Nanoparticle, Ionic bonding, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010501 environmental sciences, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Colloid, Chemical physics, Particle size, [CHIM.RADIO]Chemical Sciences/Radiochemistry, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, General Environmental Science
Abstract

International audience; Fundamental knowledge about plutonium intrinsic colloids is a key issue for the prediction of plutonium transport and release rates in the environment. Recent studies demonstrated that the particle size and surface properties of intrinsic Pu colloids are strongly influenced by the preparation method. In this work, a combination of synchrotron small angle X-ray scattering (SAXS) with X-ray absorption spectroscopy (XAS) is used to characterize two kinds of stable plutonium intrinsic colloids prepared by hydrolysis of Pu(IV) ionic species and sonolysis of PuO2 in pure water. Despite their similarities, the multi-scale structural properties of these colloidal suspensions are found to be strongly influenced by the synthesis route. The hydrolysis approach leads to spherical nanoparticles of ca. 2.0 nm, whereas sonolytic colloids show elongated structures measuring 5.7 nm of thickness and >30 nm long. This difference results from the synthesis mechanism and can be attributed to nanoparticle aggregation in the absence of capping-ions. The results obtained by both SAXS and XAS approaches converge in the description of Pu(IV) intrinsic colloids as core–shell nanoparticles made up of a PuO2 core covered with a disordered Pu–O shell characterized by a splitting of Pu–O and Pu–Pu distances and an associated strong increase of associated DWF parameters. The local distortions of both Pu–O and Pu–Pu coordination spheres observed by XAS seem to be correlated with the nanoparticle shrinking probed by SAXS rather from the contribution of higher Pu oxidation states. The stabilization of the hydrolytic colloidal particles is further suggested from SAXS simulation to result from interaction with counter-ions from the medium.

Published
2020
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19. Ultrasonically assisted conversion of uranium trioxide into uranium( vi ) intrinsic colloids

Author

Christophe Den Auwer, Xavier Le Goff, Olivier Diat, Thomas Dumas, Cyril Micheau, Manon Cot-Auriol, Philippe Moisy, Matthieu Virot, Sergey I. Nikitenko, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), Institut de Chimie de Nice (ICN), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Ions aux Interfaces Actives (L2IA), Commission des méthodes d'analyse du CEA (CETAMA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Inorganic chemistry, chemistry.chemical_element, Nanoparticle, 02 engineering and technology, Uranium, 010402 general chemistry, 021001 nanoscience & nanotechnology, Uranyl, complex mixtures, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, 13. Climate action, Uranium trioxide, Oxidizing agent, [CHIM]Chemical Sciences, Reactivity (chemistry), Leaching (metallurgy), 0210 nano-technology, Schoepite
Abstract

Under oxidizing conditions, the corrosion of spent nuclear fuel may lead to the leaching of radionuclides including soluble uranyl-based species. The speciation of the generated chemical forms is complex and the related potential formation of colloidal species appears surprisingly poorly reported in the literature. Their formation could however contribute significantly to the mobility of radionuclides in the environment. A better knowledge in the speciation and reactivity of these species appears particularly relevant. This study describes the preparation and characterization of intrinsic uranium(VI) colloids from amorphous and crystalline UO3 in pure water assisted by 20 kHz ultrasound. In the presence of carbon monoxide preventing the sonochemical formation of hydrogen peroxide, ultrasonic treatment boosts the conversion of UO3 powder into (meta-)schoepite precipitates and yields very stable and notably concentrated uranium(VI) nanoparticles in the liquid phase. Using HR-TEM, SAXS and XAS techniques, we confirmed that the colloidal suspension is composed of quasi-spherical nanoparticles measuring ca. 3.8 ± 0.3 nm and exhibiting a schoepite-like crystallographic structure. The proposed method demonstrates the possible formation of environmentally relevant U(VI) colloidal nanoparticles appearing particularly interesting for the preparation of reference systems in the absence of added ions and capping agents.

Published
2021
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20. Impact of bubble coalescence in the determination of bubble sizes using a pulsed US technique: Part 1 – Argon bubbles in water

Author

Léa Gravier, Julia Bertolo, Sergey I. Nikitenko, Rachel Pflieger, Muthupandian Ashokkumar, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), University of Melbourne, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM), Bio21 Molecular Science & Biotechnology Institute [Melbourne] (School of Chemistry), Faculty of Science [Melbourne], University of Melbourne-University of Melbourne, and This work was supported by the program for scientific mobility of the French Embassy in Australia (833171 E, 2014) and by the University of Melbourne (PRC0988 UCAB, 2015)

Subjects
Acoustics and Ultrasonics, Bubble, QC221-246, chemistry.chemical_element, 02 engineering and technology, Coalescence, 010402 general chemistry, 01 natural sciences, Sonochemistry, Inorganic Chemistry, Physics::Fluid Dynamics, Sonoluminescence, Chemical Engineering (miscellaneous), Environmental Chemistry, Radiology, Nuclear Medicine and imaging, Original Research Article, Bubble size, SDS, QD1-999, Ar, Coalescence (physics), Argon, Organic Chemistry, Acoustics. Sound, Mechanics, Radius, 021001 nanoscience & nanotechnology, Sound power, 0104 chemical sciences, Volumetric flow rate, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chemistry, chemistry, Pulsed ultrasound, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract

Highlights • An experimental method for determination of bubble sizes is thoroughly studied. • If conditions are not optimized, bubble coalescence leads to too big sizes. • The presence of a standing wave enhances coalescence. • Conditions for measurement of the ambient size of cavitation bubbles are determined. • An ambient radius of 2.9–3.0 µm is derived for Ar-saturated water at 362 kHz., A powerful experimental approach to measure the size distribution of bubbles active in sonoluminescence and/or sonochemistry is a technique based on pulsed ultrasound and sonoluminescence emission. While it is an accepted technique, it is still lacking an understanding of the effect of various experimental parameters, including the duration of the pulse on-time, the nature of the dissolved gas, the presence of a gas flow rate, etc. The present work, focusing on Ar-saturated water sonicated at 362 kHz, shows that increasing the pulse on-time leads to the measurement of coalesced bubbles. Reducing the on-time to a minimum and/or adding sodium dodecyl sulfate to water allows to reducing coalescence so that natural active cavitation bubble sizes can be measured. A radius of 2.9–3.0 µm is obtained in Ar-saturated water at 362 kHz. The effects of acoustic power and possible formation of a standing-wave on coalescence and measured bubble sizes are discussed.

Published
2021
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21. Tailoring Noble Metal-Free Ti@TiO2 Photocatalyst for Boosting Photothermal Hydrogen Production

Author

Tony Chave, Sara El Hakim, Stéphanie Roualdes, Sergey I. Nikitenko, Amr A. Nada, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Européen des membranes (IEM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Hydrogen, Titanium suboxide, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Nanomaterials, Sonohydrothermal, Photocatalysis, Hydrogen production, [CHIM.MATE]Chemical Sciences/Material chemistry, Photothermal therapy, 021001 nanoscience & nanotechnology, Nanocrystalline material, 0104 chemical sciences, Chemical engineering, chemistry, engineering, Noble metal, 0210 nano-technology
Abstract

In this work, we provide new insights into the design of Ti@TiO2photocatalyst with enhanced photothermal activity in the process of glycerol reforming. Ti@TiO2nanoparticles have been obtained by sonohydrothermal treatment of titanium metal nanoparticles in pure water. Variation of sonohydrothermal temperature allows controlling nanocrystalline TiO2shell on Ti0surface. At 100 < T < 150°C formation of TiO2NPs occurs mostly by crystallization of Ti(IV) amorphous species and oxidation of titanium suboxide Ti3O presented at the surface of Ti0nanoparticles. At T > 150°C, TiO2is also formed by oxidation of Ti0with overheated water. Kinetic study highlights the importance of TiO2nanocrystalline shell for H2generation. Electrochemical impedance spectroscopy points out more efficient electron transfer for Ti@TiO2nanoparticles in correlation with photocatalytic data. The apparent activation energy, Ea= (25–31) ± 5 kJ·mol−1, assumes that photothermal effect arises from diffusion of glycerol oxidation intermediates or from water dynamics at the surface of catalyst. Under the heating, photocatalytic H2emission is observed even in pure water.

Published
2021
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22. Sonochemical decontamination of magnesium and magnesium-zirconium alloys in mild conditions

Author

Matthieu Virot, Rachel Pflieger, Sergey I. Nikitenko, Ran Ji, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), CEA- Saclay (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Cladding (metalworking), Environmental Engineering, Materials science, Health, Toxicology and Mutagenesis, Sonication, Oxalic acid, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Corrosion, chemistry.chemical_compound, Environmental Chemistry, [CHIM]Chemical Sciences, Waste Management and Disposal, Brucite, Magnesium, Zirconium alloy, Human decontamination, 021001 nanoscience & nanotechnology, Pollution, 0104 chemical sciences, Chemical engineering, chemistry, engineering, 0210 nano-technology
Abstract

International audience; UNGG cladding nuclear wastes constitute a huge volume of Mg-based materials that raises economic and safety concerns, particularly due to their radioactivity coupled to the potential generation of H$_2$ gas under deep underground disposal. Their significant decontamination would result in more secure and less expensive storage, with a better containment of the separated long-lived radioisotopes that could enter in a classical channel. Sonication of genuine UNGG cladding materials and simulants at 345 kHz in 0.01 M oxalic acid solution (20 °C) allowed the structuring of their surfaces with the observation of homogeneously distributed craters of 20–40 $\mu$m in diameter. After a thorough characterization and comparison of the ultrasound effects generated at the surface, the various samples were artificially contaminated and characterized before sonication. The complete and rapid sonochemical decontamination of Mg-based materials was then observed, in addition to the removal of the carbon layer promoting corrosion on the inner UNGG cladding. The extension of sonication allows the neo-formed brucite (Mg(OH)$_2$) and zirconium-based phases to accumulate on the surface, thus contributing in a slight but continuous surface recontamination process. This phenomenon results from the re-adsorption of uranyl cations from the solution which can be avoided by optimizing the duration of treatment.

Published
2021
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23. Modification of Olive Leaves’ Surface by Ultrasound Cavitation. Correlation with Polyphenol Extraction Enhancement

Author

Tony Chave, Natacha Rombaut, Farid Chemat, Anne Sylvie Fabiano-Tixier, Sergey I. Nikitenko, Mohamed Ei Maâtaoui, Sécurité et Qualité des Produits d'Origine Végétale (SQPOV), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Démarche intégrée pour l'obtention d'aliments de qualité (UMR QualiSud), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)

Subjects
[SDV.BIO]Life Sciences [q-bio]/Biotechnology, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], mechanism, 01 natural sciences, lcsh:Technology, lcsh:Chemistry, chemistry.chemical_compound, 0404 agricultural biotechnology, Olive leaf, cavitation, Oleuropein, Microscopy, food processing, General Materials Science, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Instrumentation, Environmental scanning electron microscope, lcsh:QH301-705.5, Fluid Flow and Transfer Processes, Chromatography, business.industry, Chemistry, lcsh:T, ultrasound, Process Chemistry and Technology, 010401 analytical chemistry, Ultrasound, Extraction (chemistry), General Engineering, food and beverages, 04 agricultural and veterinary sciences, 040401 food science, lcsh:QC1-999, 0104 chemical sciences, Computer Science Applications, olive leaf, polyphenol, lcsh:Biology (General), lcsh:QD1-999, Polyphenol, lcsh:TA1-2040, Cavitation, microscopy, extraction, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], business, lcsh:Engineering (General). Civil engineering (General), lcsh:Physics
Abstract

We investigated the impact of ultrasound at 20 kHz on olive leaves to understand how acoustic cavitation could increase polyphenol extraction. Application of ultrasound to whole leaf from 5 to 60 min enabled us to increase extraction from 6.96 to 48.75 &micro, g eq. oleuropein/mL of extract. These results were correlated with Environmental Scanning Electron Microscopy, allowing for leaf surface observation and optical microscopy of treated leaf cross sections to understand histochemical modifications. Our observations suggest that the effectiveness of ultrasound applied to extraction is highly dependent on plant structure and on how this material will react when subjected to acoustic cavitation. Ultrasound seems to impact the leaves by two mechanisms: cuticle erosion, and fragmentation of olive leaf surface protrusions (hairs), which are both polyphenol-rich structures.

Published
2021
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24. Photocatalytic and Sonocatalytic Degradation of EDTA and Rhodamine B over Ti0 and Ti@TiO2 Nanoparticles

Author

Sergey I. Nikitenko, Tony Chave, Sara El Hakim, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Anatase, Materials science, organic pollutants, Nanoparticle, Ethylenediaminetetraacetic acid, 02 engineering and technology, TP1-1185, 010402 general chemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, photothermal, sonocatalysis, Oxidizing agent, Rhodamine B, titanium, Physical and Theoretical Chemistry, QD1-999, [SDE.IE]Environmental Sciences/Environmental Engineering, Chemical technology, EDTA, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Chemistry, chemistry, 13. Climate action, Photocatalysis, Degradation (geology), nanoparticles, 0210 nano-technology, [CHIM.OTHE]Chemical Sciences/Other, photocatalysis, Nuclear chemistry, rhodamine B, environmental remediation
Abstract

Herein, we report a comparative study of photocatalytic (Xe-lamp) and sonocatalytic (345 kHz power ultrasound) degradation of Ethylenediaminetetraacetic acid (EDTA) and Rhodamine B (RhB) in the presence of Ti0 and Ti@TiO2 core-shell nanoparticles (NPs). Ti@TiO2 NPs have been obtained by sonohydrothermal treatment (20 kHz, 200 °C) of commercially available Ti0 NPs in pure water. The obtained material is composed of quasi-spherical Ti0 particles (30–150 nm) coated by 5–15 nm crystals of anatase. In contrast to pristine TiO2, the Ti@TiO2 NPs exhibit the extend photo response from UV to NIR light region due to the light absorption by nonplasmonic Ti core. EDTA can be oxidized effectively by photocatalysis in the presence of Ti@TiO2 NPs. By contrast, air passivated Ti0 nanoparticles was found to be inactive in the photocatalytic process for both EDTA and RhB. Photocatalytic degradation of EDTA over Ti@TiO2 NPs exhibits strong photothermal effect, which has been attributed to the higher yield of oxidizing radicals produced by light at higher bulk temperature. The efficiency of RhB photocatalytic degradation depends strongly on RhB concentration. At [RhB] ≥ 1 × 10−3 M, its photocatalytic degradation is not feasible due to a strong self-absorption. At lower concentrations, RhB photocatalytic degradation is observed, but at lower efficiency compared to EDTA. We found that the efficient sonochemical degradation of RhB does not require the presence of any catalysts. For both processes, EDTA and RhB, sonochemical and photocatalytic processes are more effective in the presence of Ar/O2 gas mixture compared to pure Ar. The obtained results suggest that the choice of the optimal technology for organic pollutants degradation can be determined by their optical and complexing properties.

Published
2021
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25. Sonochemical dissolution of nanoscale ThO2 and partial conversion into a thorium peroxo sulfate

Author

Laura Bonato, Matthieu Virot, Xavier Le Goff, Philippe Moisy, Sergey I. Nikitenko, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Etude de la Matière en Mode Environnemental (L2ME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Acoustics and Ultrasonics, Organic Chemistry, Inorganic chemistry, Thorium, chemistry.chemical_element, Sulfuric acid, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Cavitation, Chemical Engineering (miscellaneous), Environmental Chemistry, [CHIM]Chemical Sciences, Radiology, Nuclear Medicine and imaging, Sulfate, 0210 nano-technology, Dissolution, Nanoscopic scale
Abstract

International audience; The influence of the sample morphology and experimental conditions towards the sonochemical dissolution of nanoscale ThO 2 samples in sulfuric acid media is described. Significant sonochemical dissolution rates and yields are observed at 20 kHz under Ar/O 2 atmosphere in dilute 0.5 M H 2 SO 4 at room temperature, contrasting with the generally-reported high refractory behavior for ThO 2. The dissolution of ThO 2 combines the physical effects driven by acoustic cavitation phenomenon, the complexing affinity of Th(IV) in sulfuric medium and the sonochemical generation of H 2 O 2. These sonochemical conditions further allow the observation of the partial conversion of ThO 2 into a scarce Th(IV) peroxo sulfate with 1D morphology resulting from one or both following processes: dissolution/ reprecipitation or formation of an intermediate Th(IV) surface complex.

Published
2020
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26. Physical and chemical characterization of shock-induced cavitation

Author

Sergey I. Nikitenko, Tony Chave, Patrick Da Costa, Hugo Dutilleul, Laureanne Parizot, M. E. Gálvez, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Combustion, Energies Propres et Turbulence (IJLRDA-CEPT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Shock wave, Water hammer, Work (thermodynamics), Yield (engineering), Materials science, Acoustics and Ultrasonics, Bubble, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Sonochemistry, Inorganic Chemistry, Chemical Engineering (miscellaneous), Environmental Chemistry, [CHIM]Chemical Sciences, Radiology, Nuclear Medicine and imaging, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Organic Chemistry, Mechanics, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Shock (mechanics), [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, 13. Climate action, Cavitation, 0210 nano-technology, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract

A strong impact on a water surface induces a shock wave propagation with a significant pressure variation leading to cavitation bubble formation. A new shock induced cavitation reactor described in this work was characterized by physical and chemical techniques. Water hammer model verification with Joukowsky approach allowed to determine the wave speed propagation and gas fraction in water submitted to shock. These values were used for frequency analysis and compared with direct bubble visualization in order to estimate the influence of the experimental parameters on the shock-induced cavitation. Thereby, the shock wave contains a broad spectrum as decomposed into frequencies. This multi-frequency nature induces heterogeneous bubbles with calculated radii of 0.01 to 3.5 mm and observed radii of 0.01 to 2.8 mm depending on experimental conditions (initial pressure, impact height, gas atmosphere). For the first time, the formation of hydroxyl radicals was proven under impact-induced cavitation. The concentration of radicals increases with increasing number of successive impacts, reaching ca. 1.3 µmol.L−1 after 500 impacts in the presence of 20% O2-Ar as saturating gas. Radical generation seems to be relatively independent of the impact height but strongly depend on the type of gas saturating water, being substantially lower in the presence of air. Moreover, radical generation increases when decreasing the initial pressure and depends on the frequency at which water is impacted by the piston. Nevertheless, yield of OH radicals during shock-induced cavitation remains much lower than that produced by power ultrasound.

Published
2020
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27. Acoustic noise spectra under hydrothermal conditions

Author

Rachel Pflieger, Sergey I. Nikitenko, Marianne Brau, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Acoustics and Ultrasonics, Bubble, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Molecular physics, Hydrothermal circulation, Spectral line, Physics::Fluid Dynamics, Inorganic Chemistry, Chemical Engineering (miscellaneous), Environmental Chemistry, Radiology, Nuclear Medicine and imaging, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], business.industry, Organic Chemistry, Ultrasound, Atmospheric temperature range, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Cavitation, Particle, Ultrasonic sensor, 0210 nano-technology, business, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract

Acoustic noise spectra were studied for the first time in overheated water using sonohydrothermal reactor operating at 20 kHz ultrasound in the temperature range from 25 to 200 °C at the autogenic pressure of 1–14 bar. The obtained results highlighted a dominating role of stable cavitation during ultrasonic treatment of hot water. Heating of sonicated water results in the formation of large number of nonlinearly oscillating bubbles synchronous with the driving frequency. At 200 °C, the acoustic spectra also display strong subharmonic and multiple ultraharmonic bands. Moreover, cavitation bubbles formed at 200 °C exhibit chaotic and random motions. It has been shown that the addition of TiO2 nanoparticles to hydrothermal water heated at 200 °C allows to eliminate subharmonic/ultraharmonic bands and stochastic oscillations as well. This effect was assigned to Pickering-like bubble stabilization due to the particle accumulation at the bubble surface.

Published
2020
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28. The Problem of Searching for Promising Production Technologies in the Field of Integrated Development of Mineral Resources in the Coal Industry

Author

Vladimir Klishin, E V Goosen, and Sergey I. Nikitenko

Subjects
Development (topology), business.industry, Field (Bourdieu), Environmental science, Production (economics), General Materials Science, Coal, Agricultural engineering, business, Mineral resource classification
Abstract

The paper offers an analysis of the problems and prospects of the most difficult branch of the Russian economy, i.e. coal industry. An attempt is made to find directions for diversifying the economy of a coal region. The authors suggested turning to the theory of value chains. The coal industry is the beginning of a chain of added value formation. The study confirmed the possibility of cooperation with the engineering industry for building new technological chains. The analysis also made it possible to put forward a hypothesis that localization on the territory of processing industries, based on related technologies within the framework of modern elongated and ramified supply chains and value chains, can become an instrument for overcoming "enclave" and reducing resource dependence of regions. Based on the analysis of patent sources, the authors defined the main directions of development of the coal industry that are currently in the focus of attention of the leading coal-mining countries and companies. On the basis of scientific research and design, the authors use the example of the Kemerovo region to determine the degree of technological development of the supported patents and the level of companies' readiness for joint projects with the machine-building industry.

Published
2019
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29. Sonochemical dissolution of nanoscale ThO

Author

Laura, Bonato, Matthieu, Virot, Xavier, Le Goff, Philippe, Moisy, and Sergey I, Nikitenko

Abstract

The influence of the sample morphology and experimental conditions towards the sonochemical dissolution of nanoscale ThO

Published
2020

30. Hierarchical Porosity Tailoring of Sol–Gel Derived Pt/SiO2 Catalysts

Author

Vasile Hulea, Siglinda Perathoner, Patrick Lacroix-Desmazes, Andrés Felipe Sierra-Salazar, Sergey I. Nikitenko, Tony Chave, André Ayral, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Européen des membranes (IEM), Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Department of Industrial Chemistry and Engineering of Materials, University of Messina, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Materials science, Latex, 02 engineering and technology, Sol–gel, 010402 general chemistry, 01 natural sciences, Catalysis, Sonochemistry, Reaction rate, Hierarchical porosity, [CHIM]Chemical Sciences, p-Chloroaniline, Porosity, Sol-gel, General Chemistry, 021001 nanoscience & nanotechnology, Pt/SiO2, Selective hydrogenation, 0104 chemical sciences, Chemical engineering, p-Chloronitrobenzene, Porosity tailoring, 0210 nano-technology, Porous medium, Mesoporous material, Selectivity
Abstract

International audience; Hierarchically porous materials offer the opportunity for catalyst development in regards to improving catalytic performances. In the present work, the combination of latex synthesis, sonochemical reduction and two-step catalysed sol–gel process has been demonstrated to be a versatile method for preparing supported catalysts with tailored hierarchical porosity. This method has been used to prepare porous Pt/SiO2 catalysts with mesopore and macropore size ranges as large as 2–15 nm and 90–400 nm, respectively. These hierarchically porous catalysts presented an excellent catalytic performance for the selective hydrogenation of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN). Selectivity values up to 100% at 80% conversion of p-CNB and initial reaction rates up to 74.0 molCNB/min molPt were obtained, while a commercial catalyst exhibited both a lower selectivity of 90.8% and a lower initial reaction rate of 47.7 molCNB/min molPt.

Published
2018
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31. Hierarchically porous Pd/SiO2 catalyst by combination of miniemulsion polymerisation and sol-gel method for the direct synthesis of H2O2

Author

Vasile Hulea, Andrés Felipe Sierra-Salazar, André Ayral, Salvatore Abate, Sergey I. Nikitenko, W.S. Jennifer Li, Patrick Lacroix-Desmazes, Tony Chave, Maël Bathfield, Siglinda Perathoner, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Industrial Chemistry and Engineering of Materials, University of Messina, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Hydrogen, H2O2, chemistry.chemical_element, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, Pd/SiO2, 01 natural sciences, Catalysis, Hierarchical porosity, chemistry.chemical_compound, Polymer chemistry, [CHIM]Chemical Sciences, Hydrogen peroxide, Porosity, ComputingMilieux_MISCELLANEOUS, Sol-gel, Chemistry (all), [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Miniemulsion polymerisation, 021001 nanoscience & nanotechnology, H2O2, Hierarchical porosity, Miniemulsion polymerisation, Pd/SiO2, Sol-gel, Catalysis, Chemistry (all), 0104 chemical sciences, Miniemulsion, [CHIM.POLY]Chemical Sciences/Polymers, Chemical engineering, chemistry, Polymerization, 0210 nano-technology, Selectivity
Abstract

The production of hydrogen peroxide H 2 O 2 , as an important commodity chemical, attires the attention towards greener processes such as the direct synthesis from hydrogen H 2 and oxygen O 2 , the selectivity being the biggest challenge. Since this reaction is structure-sensitive, the design of appropriate catalysts is required. We propose a novel method to prepare hierarchically porous Pd/SiO 2 catalyst by combination of miniemulsion polymerisation to prepare a Pd-containing latex template and sol-gel synthesis in controlled conditions to tailor the silica porosity. The final material displayed a surface area of 711 m 2 g −1 and a total pore volume of 0.93 cm 3 g −1 . The catalyst was evaluated with different pre-treatments in the direct synthesis of H 2 O 2 , where it exhibited structural resistance at the reaction conditions and a stable selectivity of 46 ± 1% towards H 2 O 2 .

Published
2018
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32. Engineering of silica-supported platinum catalysts with hierarchical porosity combining latex synthesis, sonochemistry and sol-gel process – II. Catalytic performance

Author

Salvatore Abate, Siglinda Perathoner, Patrick Lacroix-Desmazes, Sergey I. Nikitenko, Frans D. Tichelaar, Tony Chave, Vasile Hulea, André Ayral, Andrés Felipe Sierra-Salazar, Patricia J. Kooyman, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Delft University of Technology (TU Delft), Department of Industrial Chemistry and Engineering of Materials, University of Messina, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, chemistry.chemical_element, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, Sonochemistry, [CHIM]Chemical Sciences, Organic chemistry, General Materials Science, Porosity, Chloronitrobenzene, ComputingMilieux_MISCELLANEOUS, 010405 organic chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, Microporous material, Condensed Matter Physics, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, Mechanics of Materials, Platinum, Selectivity, Mesoporous material
Abstract

As a follow-up of the paper “Engineering of silica-supported platinum catalysts with hierarchical porosity combining latex synthesis, sonochemistry and sol-gel process – I. Material preparation” (A.F. Sierra-Salazar, et at., Microporous Mesoporous Mater. 234 (2016) 207–214. http://dx.doi.org/10.1016/j.micromeso.2016.07.009 ), we propose waterborne Pt-based catalysts with hierarchical porosity and controlled Pt nanoparticles (NPs) distribution within the support. The materials exhibit specific surface areas and total pore volumes as high as 490 m 2 g −1 and 0.77 cm 3 g −1 , with ∼5 nm Pt NPs mainly located in the macropores. The Pt NPs were characterised using X-ray photoemission spectroscopy (XPS) and high resolution transmission electron microscopy (HR-TEM). Considering the selectivity challenge of the catalytic hydrogenation of halonitrobenzenes to produce haloanilines, which are important raw materials for several industrial products, we evaluated these hierarchically porous catalysts for the hydrogenation of p -chloronitrobenzene ( p -CNB) in batch mode to produce p -chloroaniline ( p -CAN). It was possible to obtain up to 100% selectivity at 80% conversion and initial reaction rates up to 34 mol CNB min −1 mol Pt −1 . Such selectivity was higher than that exhibited by a commercial Pt/SiO 2 catalyst (up to 92%).

Published
2018
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33. Hypothesis about electron quantum tunneling during sonochemical splitting of water molecule

Author

R. Pflieger, Sergey I. Nikitenko, Timothé Di Pasquale, Tony Chave, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Acoustics and Ultrasonics, Hydrogen, chemistry.chemical_element, 02 engineering and technology, Electron, 010402 general chemistry, 01 natural sciences, 7. Clean energy, water splitting, Dissociation (chemistry), Sonochemistry, Inorganic Chemistry, Sonoluminescence, kinetic isotope effect, Kinetic isotope effect, Chemical Engineering (miscellaneous), Environmental Chemistry, Radiology, Nuclear Medicine and imaging, Quantum tunnelling, plasma, Organic Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry, Chemical physics, 0210 nano-technology, sonochemistry, quantum tunneling, Self-ionization of water
Abstract

International audience; Quantum tunneling in chemistry is often attributed to the processes at low or near room temperatures when the rate of thermal reactions becomes far less than the rate of quantum tunneling. However, in some rapid processes, quantum tunneling can be observed even at high temperatures. Herein, we report the experimental evidence for anomalous H/D kinetic isotope effect (KIE) during sonochemical dissociation of water molecule driven by 20 kHz power ultrasound measured in H 2 O/D 2 O mixtures saturated with Ar or Xe. Hydrogen released during ultrasonic treatment is enriched by light isotope. The observed H/D KIE (α=2.15-1.50) is much larger than what is calculated assuming a classical KIE for T g =5000 K (α=1.15) obtained from the sonoluminescence spectra in H 2 O and D 2 O. Furthermore, the α values sharply decrease with increasing of H 2 O content in H 2 O/D 2 O mixtures reaching a steady-state value close to α=1.50, which also cannot be explained by O-H/O-D zero-point energy difference. We suggest that these results can be understood in terms of quantum electron tunneling occurring in nonequilibrium picosecond plasma produced at the last stage of cavitation bubble collapse. Thermal homolytic splitting of water molecule is inhibited by extremely short lifetime of such plasma. On the contrary, immensely short traversal time for electron tunneling in water allows H 2 O dissociation by quantum tunneling mechanism.

Published
2020
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34. Effect of NaCl salt on sonochemistry and sonoluminescence in aqueous solutions

Author

Rachel Pflieger, Sergey I. Nikitenko, Muthupandian Ashokkumar, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), School of Chemistry [Melbourne], Faculty of Science [Melbourne], University of Melbourne-University of Melbourne, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Acoustics and Ultrasonics, Hydrogen, Inorganic chemistry, Salt (chemistry), chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Chemical reaction, Sonochemistry, Inorganic Chemistry, chemistry.chemical_compound, Sonoluminescence, Chemical Engineering (miscellaneous), Environmental Chemistry, [CHIM]Chemical Sciences, Radiology, Nuclear Medicine and imaging, Solubility, Hydrogen peroxide, chemistry.chemical_classification, Aqueous solution, Organic Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, 13. Climate action, 0210 nano-technology
Abstract

International audience; The presence of salts in a solution is known to affect sonochemistry, but until now no consensus has been reached in the literature on how and why a salt influences sonochemistry. The present study focuses on the effect of NaCl on sonochemical activity and sonoluminescence at 362-kHz frequency in aqueous solutions saturated with He and Ar. It is shown that the presence of salt has a multiple impact: the global population of active bubbles decreases due to the decreasing gas solubility, new chemical reactions involving Na and Cl atoms occur that influence hydrogen and hydrogen peroxide yields and the standing wave component of the US wave is enhanced, favoring sonoluminescence emission. Interestingly, the effect of salt greatly depends on the nature of the saturating gas: for instance, strong acidification occurs under He, while it is limited under Ar.

Published
2019
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35. Probing the local structure of nanoscale actinide oxides: a comparison between PuO

Author

Laura, Bonato, Matthieu, Virot, Thomas, Dumas, Adel, Mesbah, Elodie, Dalodière, Oliver, Dieste Blanco, Thierry, Wiss, Xavier, Le Goff, Michael, Odorico, Damien, Prieur, André, Rossberg, Laurent, Venault, Nicolas, Dacheux, Philippe, Moisy, and Sergey I, Nikitenko

Abstract

Actinide research at the nanoscale is gaining fundamental interest due to environmental and industrial issues. The knowledge of the local structure and speciation of actinide nanoparticles, which possibly exhibit specific physico-chemical properties in comparison to bulk materials, would help in a better and reliable description of their behaviour and reactivity. Herein, the synthesis and relevant characterization of PuO

Published
2019

36. Frontispiece: Deciphering the Crystal Structure of a Scarce 1D Polymeric Thorium Peroxo Sulfate

Author

Xavier F. Le Goff, Pierre Lecante, Thomas Dumas, Christoph Hennig, Adel Mesbah, Laura Bonato, Sergey I. Nikitenko, Damien Prieur, Nicolas Dacheux, Matthieu Virot, and Philippe Moisy

Subjects
010405 organic chemistry, Organic Chemistry, Inorganic chemistry, Thorium, chemistry.chemical_element, General Chemistry, Crystal structure, 010402 general chemistry, 01 natural sciences, Peroxide, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Sulfate
Published
2019
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37. Molecular emissions in sonoluminescence spectra of water sonicated under Ar- based gas mixtures

Author

Rachel Pflieger, Cédric Noël, Sergey I. Nikitenko, Thierry Belmonte, E. Fayard, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Sonochimie dans les Fluides Complexes (LSFC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Acoustics and Ultrasonics, Analytical chemistry, 02 engineering and technology, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Spectral line, Sonochemistry, Inorganic Chemistry, symbols.namesake, Sonoluminescence, Chemical Engineering (miscellaneous), Environmental Chemistry, Radiology, Nuclear Medicine and imaging, Emission spectrum, Spectroscopy, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Aqueous solution, Organic Chemistry, [SPI.PLASMA]Engineering Sciences [physics]/Plasmas, Plasma, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Stark effect, symbols, 0210 nano-technology
Abstract

International audience; Sonoluminescence (SL) spectroscopy is one of the very few ways to study the plasma formed in solutions submitted to ultrasound. Unfortunately, up to now only very limited emission bands were reported in SL spectra of aqueous solutions, moreover broad and badly resolved. It is shown here that by adding some N2 and/or CO2 in Ar, new molecular emissions (CN, N2 and CO) can be observed and that for some of them rovibronic temperatures can be derived. The paramount importance of Stark broadening in these emissions is underlined, together with the need for data on Stark parameters for molecular emissions.

Published
2019
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38. Deciphering the Crystal Structure of a Scarce 1D Polymeric Thorium Peroxo Sulfate

Author

Laura Bonato, Pierre Lecante, Sergey I. Nikitenko, Nicolas Dacheux, Thomas Dumas, Adel Mesbah, Philippe Moisy, Matthieu Virot, Damien Prieur, Xavier F. Le Goff, Christoph Hennig, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Interfaces de Matériaux en Evolution (LIME), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), JRC Institute for Transuranium Elements [Karlsruhe] (ITU ), European Commission - Joint Research Centre [Karlsruhe] (JRC), Etude de la Matière en Mode Environnemental (L2ME), Institute of Resource Ecology [Dresden] (IRE), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Service de Chimie des Procédés de Séparation (SCPS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)

Subjects
010405 organic chemistry, Ligand, Organic Chemistry, Thorium, chemistry.chemical_element, General Chemistry, Crystal structure, Structure type, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Peroxide, Catalysis, Synchrotron, 0104 chemical sciences, law.invention, chemistry.chemical_compound, Crystallography, chemistry, law, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Orthorhombic crystal system, Sulfate, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract

International audience; The preparation and structural characterization of an original Th peroxo sulfate dihydrate, crystallizing at room temperature in the form of stable 1D polymeric microfibres is described. A combination of laboratory and synchrotron techniques allowed solution of the structure of the Th(O2)(SO4)(H2O)2 compound, which crystallizes in a new structure type in the space group Pna21 of the orthorhombic crystal system. Particularly, the peroxide ligand coordinates to the Th cations in an unusual μ3‐η2:η2:η2 bridging mode, forming an infinite 1D chain decorated with sulfato ligands exhibiting simultaneously monodentate and bidentate coordination modes.

Published
2019
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39. Use of NH (A3Π–X3Σ−) sonoluminescence for diagnostics of nonequilibrium plasma produced by multibubble cavitation

Author

Sergey I. Nikitenko, R. Pflieger, Temim Ouerhani, Thierry Belmonte, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Thermal equilibrium, Chemistry, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, Plasma, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Spectral line, 0104 chemical sciences, Sonochemistry, Sonoluminescence, 13. Climate action, Cavitation, Electron temperature, Physical and Theoretical Chemistry, Atomic physics, [CHIM.OTHE]Chemical Sciences/Other, 0210 nano-technology, Spectroscopy
Abstract

International audience; In this work, the sonoluminescence of NH radicals has been evaluated as a new spectroscopic probe for the nonequilibrium plasma produced by multibubble cavitation in liquids. The experiments were performed in aqueous ammonia solutions subjected to power ultrasound at low and high frequencies and under two different rare gases (Ar and Xe). Sonoluminescence (SL) spectroscopy focuses on the emission of the two present systems: NH (A 3 P-X 3 S À) and OH (A 2 S +-X 2 P). Both spectroscopic systems indicate the absence of thermal equilibrium during bubble collapse (T v 4 T r) irrespective of the saturating gas. When Ar is used as the saturating gas, these emissions can be fitted using Specair software and the corresponding rovibronic temperatures are derived. Both species indicate a net increase in vibrational temperatures with the US frequency. In Xe, the SL spectra exhibit OH (C 2 S +-A 2 S +) and NH (c 1 P-a 1 D) emission bands indicating a higher electron temperature compared to Ar. However, in Xe, the SL spectra cannot be satisfactorily fitted because of significant line broadening. The estimation of the intrabubble pressure via SL simulation using Specair software is discussed. Monitoring of the sonochemical activity indicates the formation of H 2 and N 2 H 4 , while no H 2 O 2 accumulates under these conditions. In the presence of Xe, NO is also formed as a sonolysis product. The appearance of new possible reaction pathways under Xe is made possible by the higher plasma electron density and correlates with SL data.

Published
2017
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40. Characterization of Cavitation Bubbles and Sonoluminescence

Author

Rachel Pflieger, Sergey I. Nikitenko, Carlos Cairós, Robert Mettin, Rachel Pflieger, Sergey I. Nikitenko, Carlos Cairós, and Robert Mettin

Subjects
Sonoluminescence, Cavitation
Abstract

This book presents the latest research on fundamental aspects of acoustic bubbles, and in particular on various complementary ways to characterize them. It starts with the dynamics of a single bubble under ultrasound, and then addresses few-bubble systems and the formation and development of bubble structures, before briefly reviewing work on isolated bubbles in standing acoustic waves (bubble traps) and multibubble systems where translation and interaction of bubbles play a major role. Further, it explores the interaction of bubbles with objects, and highlights non-spherical bubble dynamics and the respective collapse geometries. It also discusses the important link between bubble dynamics and energy focusing in the bubble, leading to sonochemistry and sonoluminescence.The second chapter focuses on the emission of light by cavitation bubbles at collapse (sonoluminescence) and on the information that can be gained by sonoluminescence (SL) spectroscopy, e.g. the conditions reached inside the bubbles or the nature of the excited species formed. This chapter also includes a section on the use of SL intensity measurement under pulsed ultrasound as an indirect way to estimate bubble size and size distribution.Lastly, since one very important feature of cavitation systems is their sonochemical activity, the final chapter presents chemical characterizations, the care that should be taken in using them, and the possible visualization of chemical activity. It also explores the links between bubble dynamics, SL spectroscopy and sonochemical activity.This book provides a fundamental basis for other books in the Molecular Science: Ultrasound and Sonochemistry series that are more focused on applied aspects of sonochemistry. A basic knowledge of the characterization of cavitation bubbles is indispensable for the optimization of sonochemical processes, and as such the book is useful for specialists (researchers, engineers, PhD students etc.) working in the wide area of ultrasonic processing.

Published
2019

41. Toward industry 4.0 in energy sector

Author

E O Pakhomova, E V Goosen, Sergey I. Nikitenko, and E. S. Kagan

Subjects
Industry 4.0, Business, Energy sector, Industrial organization
Abstract

The article attempts to identify the profound changes occurring in the global and Russian energy sectors under the conditions of Industry 4.0. The features of the implementation of the global innovative Industry 4.0 project in the global energy sector are studied; a change in the technological basis, an upgrade of value chains and a change in business models are shown. The state and prospects of the Russian fuel and energy complex transition to a new Industry 4.0 development paradigm are analyzed. The main models and barriers to the formation of new value chains in the Russian fuel and energy complex are identified. The main niche in the Russian energy complex is highlighted, in which its development on the principles of the Industry 4.0 paradigm is possible and most likely.

Published
2020
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42. Unconventional Pathways for Designing Silica-Supported Pt and Pd Catalysts With Hierarchical Porosity

Author

Vasile Hulea, Tony Chave, Andrés Felipe Sierra-Salazar, Salvatore Abate, Sergey I. Nikitenko, Siglinda Perathoner, Patrick Lacroix-Desmazes, André Ayral, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Department of Industrial Chemistry and Engineering of Materials, University of Messina, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Green chemistry, Chemical process, Materials science, Software_GENERAL, Rational design, Pillar, Nanotechnology, 02 engineering and technology, [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Environmentally friendly, 0104 chemical sciences, Catalysis, [CHIM.POLY]Chemical Sciences/Polymers, 0210 nano-technology, Porosity, Hierarchical porous, ComputingMilieux_MISCELLANEOUS
Abstract

Catalysis as a pillar of green chemistry is called on to improve the performance of the current chemical processes and to develop new and sustainable processes and products. In order to tackle the current challenges in sustainable chemistry, catalyst rational design approaches are necessary. Such approaches require tailoring tools for the catalyst preparation, which should also be environmentally friendly. This chapter starts by a brief review of the techniques for texture tailoring and catalyst functionalization, highlighting the high potential of hierarchical porous catalysts. Then, a few innovative techniques for the preparation of silica-supported Pt and Pd catalysts with hierarchical porosity are described.

Published
2019
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44. Diagnosing the plasma formed during acoustic cavitation in [BEPip][NTf2] ionic liquid

Author

Micheline Draye, Thierry Belmonte, Sergey I. Nikitenko, Manuel Lejeune, Rachel Pflieger, Cédric Noël, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire LCME / Equipe Chimie Verte (LCME_CV), Laboratoire de Chimie Moléculaire et Environnement (LCME), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS]Physics [physics], Materials science, Sonication, [SPI.PLASMA]Engineering Sciences [physics]/Plasmas, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, Plasma, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Spectral line, 0104 chemical sciences, Sonochemistry, chemistry.chemical_compound, Sonoluminescence, chemistry, Cavitation, Excited state, Ionic liquid, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

International audience; Sonoluminescence (SL) spectra of a very dry [BEPip][NTf 2 ] ionic liquid were measured in the first minutes of sonication under Ar. The intense sonoluminescence allowed us to monitor the time-evolution of the SL spectra. Several molecular emissions were observed. Rovibronic temperatures of C 2 and CN were determined giving vibrational temperatures of 5800 AE 500 K and 6000 AE 500 K and rotational temperatures (i.e. translational or gas temperatures) of 4000 AE 500 K. These temperatures stay remarkably constant during the sonolysis, while SL spectra undergo strong changes that illustrate the very fast evolution of the plasma during the first minutes of sonication. The expected strong decrease in the plasma electron energy also reflects in the evolution of the populations of CH electronically excited states. The physical meaning of temperatures derived from molecular emissions in SL spectra is discussed.

Published
2019
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45. Probing the Local Structure of Nanoscaled Actinide Oxides: A Comparison between PuO2 and ThO2 Nanoparticles Rules out PuO2+x Hypothesis

Author

Thierry Wiss, Laurent Venault, Philippe Moisy, Thomas Dumas, Adel Mesbah, Oliver Dieste Blanco, Matthieu Virot, Damien Prieur, Laura Bonato, Xavier F. Le Goff, Sergey I. Nikitenko, Elodie Dalodière, Michael Odorico, Nicolas Dacheux, André Rossberg, CEA, Contributeur MAP, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Northwestern University [Evanston], European Commission - Joint Research Centre [Karlsruhe] (JRC), Etude de la Matière en Mode Environnemental (L2ME), European Synchrotron Radiation Facility (ESRF), Département RadioChimie et Procédés (DRCP), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Interfaces de Matériaux en Evolution (LIME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Institut des Sciences et technologies pour une Economie Circulaire des énergies bas carbone (ISEC)

Subjects
[CHIM.INOR] Chemical Sciences/Inorganic chemistry, Materials science, Oxide, Nanoparticle, Bioengineering, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Colloid, chemistry.chemical_compound, [CHIM.RADIO] Chemical Sciences/Radiochemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, Reactivity (chemistry), [CHIM.CRIS] Chemical Sciences/Cristallography, ComputingMilieux_MISCELLANEOUS, [CHIM.MATE] Chemical Sciences/Material chemistry, Extended X-ray absorption fine structure, General Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Actinide, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Characterization (materials science), Nanocrystal, chemistry, Chemical physics, 0210 nano-technology, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract

International audience; Actinide research at the nanoscale is gaining fundamental interest due to environmental and industrial issues. The knowledge of the local structure and speciation of actinide nanoparticles, which possibly exhibit specific physico-chemical properties in comparison to bulk materials, would help in a better and reliable description of their behaviour and reactivity. Herein, the synthesis and relevant characterization of PuO2 and ThO2 nanoparticles displayed as dispersed colloids, nanopowders or nanostructured oxide powders, allow to establish a clear relationship between the size of the nanocrystals composing these oxides and their corresponding An(IV) local structure investigated by EXAFS spectroscopy. Particularly, the probed An(IV) first oxygen shell evidences an analogous behaviour for both Pu and Th oxides. This observation suggests that the often observed and controversial splitting of the Pu-O shell on the Fourier transformed EXAFS signal of PuO2 samples is attributed to a local structural disorder driven by a nanoparticle surface effect rather than to the presence of PuO2+x species.

Published
2019
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46. Sonocatalytic oxidation of EDTA in aqueous solutions over noble metal-free Co$_3$O$_4$/TiO$_2$ catalyst

Author

Hugo Dutilleul, Laureanne Parizot, Patrick Da Costa, Tony Chave, M. E. Gálvez, Sergey I. Nikitenko, Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Iminodiacetic acid, Formic acid, Oxalic acid, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Acetic acid, Ultrasound, Glycolic acid, General Environmental Science, Heterogeneous catalysis, Aqueous solution, [SDE.IE]Environmental Sciences/Environmental Engineering, Process Chemistry and Technology, technology, industry, and agriculture, EDTA, Advanced oxidation processes, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, engineering, Noble metal, 0210 nano-technology, Nuclear chemistry, Sonochemistry
Abstract

International audience; The sonocatalytic degradation of EDTA in aqueous solution was studied under ultrasound irradiation (345 kHz, 73 W, acoustic power 0.20 W·mL$^{−1}$, Ar and Ar/O$_2$ saturating gases, T = 20–50 °C) in the presence of Co$_3$3O$_4$/TiO$_2$ and Pt/TiO$_2$ nanocatalysts. About 90% of EDTA (C$_0$ = 5 10$^{-3}$ M) was oxidized during ultrasonic treatment at 40 °C in the presence of the Co$_3$O$_4$/TiO$_2$ catalyst and Ar/O$_2$ gas mixture. By contrast, Pt/TiO$_2$ catalyst exhibited much lower sonocatalytic activity in this system. Suggested mechanism of EDTA oxidation in the presence of Co$_3$O$_4$/TiO$_2$ catalyst involved the generation of oxidizing radicals by acoustic cavitation and Co(II)-Co(III) redox process. Quite low apparent activation energy of the sonocatalytic process (E$_a$ = 19 kJ mol$^{−1}$) was attributed to diffusion of reagents in the vicinity of the active sites of catalyst. Sonocatalytic degradation of EDTA is accompanied by formation of iminodiacetic acid, formic acid, oxalic acid, glycolic acid and acetic acid as intermediate products in an agreement with radical-driven mechanism.

Published
2019
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49. Insights into the Photothermal Hydrogen Production from Glycerol Aqueous Solutions over Noble Metal-Free Ti@TiO 2 Core-Shell Nanoparticles

Author

Tony Chave, Xavier Le Goff, Sergey I. Nikitenko, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Hydrogen, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, Photochemistry, 01 natural sciences, 7. Clean energy, Catalysis, General Materials Science, Hydrogen production, Aqueous solution, Photothermal effect, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, 13. Climate action, engineering, Photocatalysis, Noble metal, 0210 nano-technology
Abstract

International audience; Photocatalytic production of hydrogen from renewable sources with platinum group metal‐free catalysts is of great importance for environmentally friendly energetics. Herein, Ti@TiO2 core–shell nanoparticles prepared by sonohydrothermal treatment of titanium metal nanoparticles are examined for hydrogen generation from aqueous glycerol solutions under vis/NIR light irradiation. It is shown that photocatalytic reforming of glycerol in the presence of Ti@TiO2 exhibits strong photothermal effect allowing more efficient use of solar energy. Apparent activation energy equal to E act = 27 ± 2 kJ mol−1 indicates that the thermal effect is related to the diffusion of reaction intermediates at catalyst surface rather than to the activation of chemical bonds. The photoexcitation mechanism of Ti@TiO2 particles involves interband transitions in nonplasmonic Ti metal core followed by nonradiative Landau damping. Effective electron–hole separation between Ti core and nanocrystalline TiO2 anatase shell in Ti@TiO2 nanoparticles is confirmed by photoluminescence spectroscopy. In studied system, photothermal hydrogen production is not accompanied by CO2 emission indicating that glycerol is oxidized to glyceric acid without further decarboxylation.

Published
2018
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50. Inverse effects of the gas feed positioning on sonochemistry and sonoluminescence

Author

Rachel Pflieger, Gilles Guillot, Muthupandian Ashokkumar, Sergey I. Nikitenko, Léa Gravier, Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Melbourne, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Acoustics and Ultrasonics, Flow (psychology), 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Sonochemistry, Inorganic Chemistry, Sonoluminescence, Chemical Engineering (miscellaneous), Environmental Chemistry, Radiology, Nuclear Medicine and imaging, Solubility, Spectroscopy, ComputingMilieux_MISCELLANEOUS, geography, Aqueous solution, geography.geographical_feature_category, Organic Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Inlet, 0104 chemical sciences, Chemical physics, 0210 nano-technology, Intensity (heat transfer)
Abstract

Purging of solutions to enhance sonochemical reactions is a common practice. A fundamental study combining sonoluminescence spectroscopy and sonochemical activity is adopted to study the effects of continuous Ar gas flow in the solution and of the position of the gas inlet tube on high-frequency sonolysis of aqueous solutions. It has been observed that neither sonochemical activity nor sonoluminescence intensity is controlled by the gas solubility only. Besides, the change in position of the gas inlet tube leads to opposite effects in sonoluminescence intensity and sonochemical activity: while the former increases, the latter decreases. Such an observation has never been reported despite sonochemical reactions have been carried out under different gas environments. Sonoluminescence spectroscopy indicates that more extreme conditions are reached at collapse with the gas inlet on the side, which could be explained by a more symmetrical collapse. Finally, it is shown in certain conditions that it is possible to favor the formation of some sonochemical products simply by positioning the gas inlet at different positions, which has practical significance in designing large scale sonochemical reactors for industrial applications.

Published
2018
Full Text
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