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International audience; The determination of the abundances of the CHx, C=O and aromatic groups in chondritic Insoluble Organic Matter (IOM) and coals by Infrared (IR) spectroscopy is a challenging issue due to insufficient knowledge on the absorption cross-sections and their sensitivity to the molecular environment. Here, we report a calibration approach based on a 13C synthetic model material whose composition was unambiguously determined by Direct-Pulse/Magic Angle Spinning Nuclear Magnetic Resonance (DP/MAS NMR). Ratios of the cross-sections of the CHx, C=O and aromatic groups have been determined, and the method has been applied to IOM samples extracted from four chondrites as Orgueil (CI), Murchison (CM), Tagish Lake (C2-ungrouped) and EET 92042 (CR), and to a series of coals. The estimate of the aliphatic to aromatic carbon ratio (nCHx/nAro) in IOM samples from Orgueil, Murchison and Tagish Lake chondrites is in good agreement with Single-Pulse/NMR estimates earlier published, and is lower by a factor of 1.3 in the case of the CR chondrite EET 92042 (but the error bars overlap). In contrast, the aliphatic to carbonyl ratio (nCHx/nC=O) is overestimated for the four chondrites. These discrepancies are likely due to the control of the absorption cross-section of the C=O and C=C bonds by the local molecular environment. Regarding coals, the use of published NMR analyses has brought to light that the integrated cross-section ratio ACHx/AAro varies with the vitrinite reflectance over an order of magnitude. Here as well, the local oxygen speciation plays a critical control in AAro, which decreases with increasing the vitrinite reflectance. We provide an analytical law that links ACHx/AAro and vitrinite reflectance, which will allow the determination of nCHx/nAro for any coal sample, provided its vitrinite reflectance is known.

We report the design and synthesis of europium-doped gadolinium oxysulfide nanoscintillators Gd2 O2 S:Eu3+ conjugated with two different photosensitizers (PSs): a zinc chlorin (ZnTPC) and a zinc phtalocyanine (ZnPc) by covalent bonding through a layer of N-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA). These conjugates were designed to be activated under X-ray excitation to allow a photodynamic effect, although this desired outcome was not achieved in this study. The monodispersed nanoparticles of ∼70 nm diameter were pegylated to be stabilized in aqueous suspension. It was shown that the PSs conserved their photophysical properties once conjugated to the nanoscintillator and efficient singlet oxygen was obtained upon photo-irradiation. However, no energy transfer was observed from the nanoscintillator to the photosensitizer neither under photo- nor X-ray irradiation.

International audience; This study aims to characterize the sedimentation velocity and the rheology of suspensions of hematite particles suspended in strongly alkaline media at 100 and 110 degrees C, as done for an alternative electrochemical process in development for iron production by direct electrode reduction of hematite. Considering the medium used in the process, i.e. 12% (v/v) suspension of hematite particles in 50% sodium hydroxide aqueous, the sedimentation velocity of hematite particle at 110 degrees C is 0.010 mm/s, which is very slow because the average size of the solid particles is around 10 mu m and the significant collisions and inter-actions occuring between the particles in the concentrated suspension. Two geometries were used to characterize the theological behavior of the apparent viscosity of the suspension of 12% (v/v) (i.e. 33 wt%) at 100 degrees C: a conventional Couette geometry and a helical ribbon mixer. The suspension was found shear thinning in the range of shear rate studied. The rheological behavior of the suspension can be described by a power-law model. The apparent viscosity of the hematite suspension estimated at a shear rate between 0.5 and 10 s(-1) is between 100 and 20 mPa s for the two geometries. The apparent viscosity calculated from the terminal velocity of 10 mu m particles is of the same order of magnitude of the results obtained with the two rheometer configurations. The effect of the particle concentration on the sedimentation velocity and viscosity of the hematite suspensions was also studied.

International audience; Continuous hydrothermal flow synthesis process has shown great advantages concerning the control of particle size and morphology through the optimization of supercritical water processing parameters. In particular, micromixing is a key issue of the process for controlling the nucleation mechanism. A Computational Fluid Dynamics (CFD) model is suggested for nanoparticle size determination using a population balance approach. Models for reaction kinetics, thermodynamics, nucleation and growth are presented. The effects of base concentration and hydrodynamics are investigated. Results show that the CFD may be valuable simulation tool for controlling the size and the shape of nanoparticles from a good adjustment of processing parameters. However, some additional knowledge on nucleation, crystal growth and aggregation mechanisms are useful in order to get a better agreement.

International audience; This paper presents energy transfer occurring in small organically modified core-shell nanoparticles (core lanthanide oxide, shell polysiloxane) (diameter < 10 nm) conjugated with photosensitizers designed for photodynamic therapy applications. These nanoparticles covalently encapsulate a photosensitizing PDT drug in different concentrations. Stable dispersions of the nanoparticles were prepared and the photophysical properties of the photosensitizers were studied and compared to those of the photosensitizers in solution. Increasing the photosensitizer concentration in the nanoparticles was not found to cause any changes in the absorption properties while fluorescence and singlet oxygen quantum yields decreased. As a possible explanation, we have suggested that both long distance energy transfer such as FRET and self-quenching could occur into the nanoparticles. A simple "trend" model of this kind of energy transfer complies with results of experiments on steady state fluorescence and singlet oxygen luminescence.

International audience; The purpose of this study was to evaluate the mixing characteristics of a new milliliter-scale (mL-scale) reactor developed for studying enzymatic activity or physiological cell response. The mL-scale reactor was designed to enable the integration of several sensors to carry out dynamic measurements in a controlled environment. Rapid homogeneity of the entire system is essential to ensure reproducible and reliable results, consequently the reactor was stirred to optimize both mass and heat transfers. A comparative study using three different techniques was undertaken to study mixing performances in the system. Firstly, mixing time (4,) was estimated in the reactor using both experimental methods, including instrumental method and image analysis, and CFD. As hydrodynamics is not occurring in the fully-turbulent regime, turbulent numerical simulations using the SST transitional and the standard k-epsilon turbulence models were conducted and compared to laminar approach. Results showed good agreement between the two experimental methods and no significant differences were observed between the simulation methods. Moreover, according to results, a minimum agitation rate of 350 rpm seemed to be appropriated to obtain a quick homogenization in the system. Finally, the second part of the study seemed to indicate that probes had no significant impact in the studied reactor.

International audience; This work aims at investigating the breakup dynamics of the ferrofluid droplet under magnetic fields in a microfluidic T-junction. The whole breakup processes of the ferrofluid droplets under uniform magnetic field and non-uniform magnetic field were exhaustively considered. The influence of both the flow rates and magnetic flux density on the formation and breakup were extensively studied. It was found that the type of breakup process can be changed and the breakup frequency of ferrofluid droplets can be actively modulated by applying a uniform magnetic field. While under non-uniform magnetic field, the asymmetric breakup of ferrofluid droplets can be realized. Both the magnetic field intensity and hydrodynamic force affect the asymmetry of the breakup process. The non-uniform magnetic field can exert attraction on ferrofluid droplets in a dissymmetrical way to avoid breakup.

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Nowadays, superhydrophobicity has been the limelight of the academic community owing to the plethora of applications. In this work, the downhill motion of liquid drops and liquid marbles was investigated by two distinct particle-laden interfaces. Liquid drops and liquid marbles accelerate firstly and then move on the slope with a steady velocity which decreases with the liquid viscosity. The steady velocity of liquid marbles is lower than that of liquid drops while the maximum aspect ratio of liquid marbles is higher than that of liquid drops, due to different interface interactions. The particles on the solid substrate enhance the motion of liquid drops while those on the liquid surface reduce the surface tension of liquid marbles. Both liquid drops on non-stick solid surface and non-stick liquid marbles on solid substrate could provide theoretical basis for the precisely targeted transportation of small quantities of liquids by particle-laden interfaces, especially in chemical and biomedical applications.

The present work aims at studying the nonlinear breakup mechanism for Taylor bubble formation in a microfluidic flow-focusing device by using a high-speed digital camera. Experiments were carried out in a square microchannel with cross section of 600 × 600 μm. During the nonlinear collapse process, the variation of the minimum radius of bubble neck (r 0) with the remaining time until pinch-off (τ) can be scaled by a power–law relationship: $$r_{0} \propto \tau^{\alpha } .$$ Due to the interface rearrangement around the neck, the nonlinear collapse process can be divided into two distinct stages: liquid squeezing collapse stage and free pinch-off stage. In the liquid squeezing collapse stage, the neck collapses under the constriction of the liquid flow and the exponent α approaches to 0.33 with the increase in the liquid flow rate Q l. In the free pinch-off stage, the value of α is close to the theoretical value of 0.50 derived from the Rayleigh–Plesset equation and is independent of Q l.

International audience; The present work studies the bubble formation in viscous liquids with the viscosity ranging from 5 to 400 mPa s by using a high-speed digital camera. The experiment was carried out in a flow-focusing device with square cross-section of 600 x 600 mu m. Results show that the viscous shear stress strongly influences the dynamics of bubble formation, including the shape and size of bubbles. The bubble size follows power-law relations with the gas flow rate, the flow rate and viscosity of the liquid phase respectively, indicating that bubbles formed in viscous fluids are controlled by a combination of squeezing mechanism and shearing mechanism. Therefore, the bubble size can be predicted by a power law function depending on the flow rate ratio of gas and liquid phases phi representing the squeezing mechanism and capillary number Ca representing the shearing mechanism. In addition, the dynamics of bubble formation in viscous liquids in a flow focusing device is also analyzed.

International audience; The effect of confinement on the droplet formation in T junctions was studied for three configurations of fluid injection. The sizes of the main droplets and the satellite droplets were measured in the squeezing and dripping regimes. The evolution of droplet sizes with capillary number in the continuous phase is similar to that in flow-focusing junctions, i.e., the size of the main droplets decreases with an increase of this capillary number, while the size of the satellite droplets increases with an increase of this capillary number. While in the range of flow rates investigated the injection configuration does not exhibit a significant effect on the main droplet sizes, it does have an effect on the size of the satellite droplets. The latter ones are smaller when the neck rupture of the droplet occurs on an angle of the microsystem.

International audience; Doping of transition metals within a semiconductor quantum dot (QD) has a high impact on the optical and magnetic properties of the QD. In this study, we report the synthesis of Mn 2+-doped Ag−In−Ga−Zn−S (Mn:AIGZS) QDs via thermolysis of a dithiocarbamate complex of Ag + , In 3+ , Ga 3+ , and Zn 2+ and of Mn(stearate) 2 in oleylamine. The influence of the Mn 2+ loading on the photoluminescence (PL) and magnetic properties of the dots are investigated. Mn:AIGZS QDs exhibit a diameter of ca. 2 nm, a high PL quantum yield (up to 41.3% for a 2.5% doping in Mn 2+), and robust photo-and colloidal stabilities. The optical properties of Mn:AIGZS QDs are preserved upon transfer into water using the glutathione tetramethylammonium ligand. At the same time, Mn:AIGZS QDs exhibit high relaxivity (r 1 = 0.15 mM −1 s −1 and r 2 = 0.57 mM −1 s −1 at 298 K and 2.34 T), which shows their potential applicability for bimodal PL/magnetic resonance imaging (MRI) probes.

International audience; Tb2O3 coated with a polysiloxane layer is a biocompatible nanoscintillator that exhibits an appropriate pattern of biodistribution after injection. In this contribution, we combine this nanosystem with porphyrin molecules that are able to generate singlet oxygen, a major cytotoxic agent for photodynamic therapy application. Using time-resolved laser spectroscopy and singlet oxygen probes, we demonstrate this combination is suitable for singlet oxygen generation induced by X-ray and provide a physical study of the energy transfer observed between the nanoscintillator and the porphyrin. Combined with a radiotherapy protocol, the proposed nanohybrid system presents a combination of physical, chemical, and biological properties that make it a good candidate for photodynamic effects in deep tissues.

International audience; The formation of gas bubbles in a liquid is of both academic and industrial interest, and sets the initial conditions for the hydrodynamics, heat and mass transfer as well as chemical reactions from a dispersed gaseous phase to the liquid phase in industrial processes. The literature on bubble formation from a single submerged orifice is large in both Newtonian and non-Newtonian fluids. Despite the numerous theoretical and experimental investigations, the mechanisms of bubble growth and detachment remain far from fully understood. The study of bubble formation at micro-scale and especially in the presence of a lateral liquid flow field is still very limited. This is the topic for consideration in the present paper. In particular, this study compares both qualitatively and quantitatively the formation of bubbles at micro- and macro-scales. A high-speed digital camera (up to 10,000 images s(-1)), a micro-Particle Image Velocimetry (mu-PIV) system and also a macro-PIV (PIV) were employed in this work, to measure the velocity flow field at micro- and macro-scales. At macro-scale, experiments were conducted in a square Altuglas column of 0.1 m filled with water or viscous Emkarox solutions using different orifice sizes and various gas flowrates. A rotating device above the orifice in the column was used to impose a shear flow on the forming bubble at the orifice. At micro-scale, different sizes of micro-reactors (600 and 1000 mu m) and different micro-devices were employed to compare the mechanism of bubble formation. A correlation based on dimensionless numbers was proposed to estimate the formed bubble volume at micro- and macro-scales in order to reveal the main factors governing the formation mechanisms.

International audience; The motion and interactions of three equal-interval parallel bubbles in non-Newtonian fluids were numerically simulated by volume of fluid method (VOF), in which the continuous surface tension model and the power-law model were adopted to represent surface tension and rheological properties of non-Newtonian fluids, respectively. The computational method was validated by the comparison of the processes of coalescence of two in-line bubbles and rising of two parallel bubbles between experiment and simulation. This method was then applied to study the effect of initial bubble diameter, initial horizontal bubble interval and rheological properties of non-Newtonian fluids on lateral coalescence and rising of three parallel bubbles. The dimensionless critical horizontal interval of bubble coalescence was obtained under different physical property conditions. The critical horizontal interval of bubble coalescence decreases with the increase of initial bubble diameter and flow index of non-Newtonian fluids. When the initial horizontal bubble interval is less than the critical horizontal interval of bubble coalescence, three bubbles will coalesce into a bigger bubble. The coalescing bubble could breakup into two identical daughter bubbles when the initial bubble diameter was increased or the flow index of non-Newtonian fluids was decreased. Three parallel bubbles rising in non-Newtonian fluids will experience repulsive interactions once the initial horizontal bubble interval is greater than the critical horizontal interval of bubble coalescence, the horizontal bubble interval increased gradually owing to the repulsive effect, while the vertical distance between bubbles varied dramatically for spherical bubble and ellipsoidal bubble due to the differences of their flow field structures.

Process intensification has emerged as a strategy to satisfy the objectives of process efficiency, sustainable development and economic competitiveness. Unfortunately, intensified technologies are too numerous to fit in a time-constrained academic syllabus. For high pedagogic impact, appropriate case studies should be favored to cover a wide range of strategies while demonstrating these opportunities, using accessible tools and concepts. The developed case study demonstrates the gain of sustainability offered by applying multi-scale design to a cyclonic separation, enabling miniaturization at constant efficiency. The analysis leads to well-known multi-cyclonic systems. This example is particularly striking for students since multi-cyclonic vacuum cleaners are a domestic illustration of this strategy. The analysis aims to miniaturize the separator, at constant efficiency and dissipated mechanical power. By applying a scale factor to cyclone dimensions, while maintaining the efficiency, a first strategy demonstrates that miniaturization alone cannot be sustainable. The best strategy considers parallel miniature cyclones, which enables to satisfy all objectives: the volume and dissipated mechanical power can be reduced simultaneously, requiring a multi-objective optimization. Scenarios for integration of the case study in various curricula are proposed, by differentiating the learning outcomes as a function of student level and course objectives.

International audience; Photodynamic therapy (PDT) is an emerging theranostic modality for various cancer as well as non-cancer diseases. Its efficiency is mainly based on a selective accumulation of PDT and imaging agents in tumor tissue. The vascular effect is widely accepted to play a major role in tumor eradication by PDT. To promote this vascular effect, we previously demonstrated the interest of using an active- targeting strategy targeting neuropilin-1 (NRP-1), mainly over-expressed by tumor angiogenic vessels. For an integrated vascular-targeted PDT with magnetic resonance imaging (MRI) of cancer, we developed multifunctional gadolinium-based nanoparticles consisting of a surface-localized tumor vasculature targeting NRP-1 peptide and polysiloxane nanoparticles with gadolinium chelated by DOTA derivatives on the surface and a chlorin as photosensitizer. The nanoparticles were surface-functionalized with hydrophilic DOTA chelates and also used as a scaffold for the targeting peptide grafting. In vitro investigations demonstrated the ability of multifunctional nanoparticles to preserve the photophysical properties of the encapsulated photosensitizer and to confer photosensitivity to MDA-MB-231 cancer cells related to photosensitizer concentration and light dose. Using binding test, we revealed the ability of peptide-functionalized nanoparticles to target NRP-1 recombinant protein. Importantly, after intravenous injection of the multifunctional nanoparticles in rats bearing intracranial U87 glioblastoma, a positive MRI contrast enhancement was specifically observed in tumor tissue. Real-time MRI analysis revealed the ability of the targeting peptide to confer specific intratumoral retention of the multifunctional nanoparticles.

International audience; Direct information about fluids under supercritical water conditions is unfeasible due to the engineering restrictions at high pressure and high temperature. Numerical investigations based on computational fluid dynamics (CFD) calculations are widely used in order to get extensive information on the fluid behavior, particularly to help the design of a new reactor. This paper presents the numerical investigations performed on an original supercritical water device, especially in the level of the reactor. CFD calculations allow to design and optimize the present reactor described in this study. Currently, this process produces some nanometric oxide powders in continuous way with a production rate of 10-15g h(-1). Examples of synthesized nanomaterials are presented in order to prove the process efficiency. Crystalline ZrO(2) and TiO(2) were produced from a metallic salt and an organometallic as precursors, respectively. XRD and HRTEM analyses show nanosized particles with an uniform size distribution (

Aim: The strategy developed aims to favor the vascular effect of photodynamic therapy by targeting tumor-associated vascularization using peptide-functionalized nanoparticles. We previously described the conjugation of a photosensitizer to a peptide targeting neuropilin-1 overexpressed in tumor angiogenic vessels. Materials & Methods: In this study, we have designed and photophysically characterized a multifunctional nanoparticle consisting of a surface-localized tumor vasculature targeting peptides and encapsulated photodynamic therapy and imaging agents. Results & Conclusion: The elaboration of these multifunctional silica-based nanoparticles is reported. Nanoparticles functionalized with approximately 4.2 peptides bound to recombinant neuropilin-1 protein. Nanoparticles conferred photosensitivity to cells overexpressing neuropilin-1, providing evidence that the chlorin grafted within the nanoparticle matrix can be photoactivated to yield photocytotoxic effects in vitro.

International audience; The adsorption of a sunflower protein extract at two air− water and oil−water interfaces is investigated using tensiometry, dilational viscoelasticity, and ellipsometry. For both interfaces, a three step mechanism was evidenced thanks to master curve representations of the data taken at different aging times and protein concentrations. At short times, a diffusion limited adsorption of proteins at interfaces is demonstrated. First, a two-dimensional protein film is formed with a partition of the polypeptide chains in the two phases that depends strongly on the nature of the hydrophobic phase: most of the film is in the aqueous phase at the air−water interface, while it is mostly in the organic phase at the oil−water interface. Then a three-dimensional saturated monolayer of proteins is formed. At short times, adsorption mechanisms are analogous to those found with typical globular proteins, while strong divergences are observed at longer adsorption times. Following the saturation step, a thick layer expands in the aqueous phase and appears associated with the release of large objects in the bulk. The kinetic evolution of this second layer is compatible with a diffusion limited adsorption of the minor population of polymeric complexes with hydrodynamic radius R H ∼ 80 nm, evidenced in equilibrium with hexameric globulins (R H ∼ 6 nm) in solution. These complexes could result from the presence of residual polyphenols in the extract and raise the question of the role of these compounds in the interfacial properties of plant protein extracts.

The unique geometry of screw extruders allows handling very viscous media; thus, they can be used as continuous reactors to conduct polymerization reactions without using any solvents. This is call...

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International audience; A theoretical study of the thermal decomposition of β-1,4-xylan, a model polymer of hemicelluloses, is proposed for the first time. A mechanism based on unimolecular concerted reactions is elaborated in a comprehensive way. Elementary reactions, such as dehydrations, retro-aldol, retro Diels–Alder, retro-ene, glycosidic bond fissions, isomerizations, etc., are applied to β-1,4-xylan, as well as to the fragments formed. At each stage of the construction of the mechanism, the fragments previously retained are decomposed and the low energy paths are selected to define new fragments. Energy barriers are computed at the CBS-QB3 level of theory and rate coefficients of important reactions are calculated. It is shown that the main reaction pathways can be modelled by reactions involving two specific fragments, which react in closed sequences, similarly to chain-propagating reactions. The proposed reaction scheme allows to predict important species observed during the pyrolysis of xylan, such as aldehydes or CO. In addition, we show that dehydrations require high activation energy and cannot compete with the other reactions. Therefore, it seems difficult to explain, by means of unimolecular homogeneous gas phase reactions, the significant formation of specific species such as furfural as reported by several authors.

International audience; Urea is used in Selective Catalytic and Non Catalytic Reduction (SCR and SNCR) methods for NOx abatement in post-combustion processes. The decomposition of urea-water solution in exhaust systems leads to the formation of NH3, which is the NOx reducing agent. However, the decomposition of urea can also lead to the formation of unwanted pyrolysis by-products, particularly in region where the temperature and pressure conditions are not optimal or via wall-spray interactions. In this study, a gas phase kinetic model for urea pyrolysis is proposed to explain the growth of pyrolysis by-products of urea, and in particular, the route of formation of the major product: isocyanuric acid. Systematic theoretical calculations, using electronic structure calculations and transition state theory, were performed to explore all the possible unimolecular and bimolecular reactions of the initial species. Kinetic modeling was used to select the relevant reaction pathways at each growing step, and their rate constants were refined using CCSD(T)/CBS//B2PLYP-D3/cc-pvTZ calculations. Quantum calculations showed that the postulated growing schemes of the literature, based on the successive urea + HNCO ⇆ biuret, biuret + HNCO ⇆ triuret followed by the cyclization of triuret into isocyanuric acid are not energetically favored. It is observed that the most favored reaction route to isocyanuric acid involves carbamimidic acid, the urea tautomer, that first yields biuret in a reaction with HNCO and then is involved in the formation of triuret by reacting with a decomposition product of biuret. Isocyanuric acid is produced from the reaction between HNCO and the same decomposition product of biuret. This new mechanism of formation of isocyanuric acid is tested at different conditions to explore its most favored conditions of formation in the gas phase. Exploratory simulations of a pseudo condensed phase are also performed to qualitatively simulate condensed phase experiments and explain the observed pyrolysis yields.

As a result of their intrinsic compl5exity and their severe consequences, the study of hybrid mixture explosions requires the consideration of several additional factors and parameters than the study of gas-only and dust-only explosions. The main objective of this work is to perform an exhaustive analysis of the explosion severity of wheat starch/pyrolysis gases hybrid mixtures in the context of the 20-L Sphere Test and to determine how severe hybrid mixture explosions can be when compared to one phase explosions. Several experimental tests were performed at different concentrations of both phases and at fixed operating conditions of ignition delay time (tv) and nozzle geometry. CFD simulations from a previously-validated model were run alongside in order to complement the experimental findings and expand the understanding of the hybrid system as a whole, especially in terms of the development and interaction of the phases’ chemical reactions. The experimental and CFD data were analysed using severity maps and adapted stoichiometric parameters proposed in the literature. It was found that the explosion regimes proposed in the literature are not universally-applicable to all types of hybrid mixtures, given that, for wheat starch/pyrolysis gases hybrid mixtures, each regime could not be uniquely characterized and differences in the explosion behaviour were observed within the same regime. In contrast, it was found that analysing the data in terms of parameters that take into account the nature of the chemical reactions of the phases is a superior methodology given that it provides a more rigorous comparative basis for assessing the explosion severity of different types of combustible materials, including hybrid mixtures.

International audience; This purpose of this review is to provide a short overview of electrochemical reduction processes for oxidized contaminants in water. The major parameters affecting the electro-reduction mechanisms and the impact of electrode choice are discussed with reference to both inorganic and organic pollutants that are either regulated or emerging (e.g., non-metal oxyanions, per-and polyfluoroalkyl substances (PFAS)). To conclude, a discussion is presented on the future directions and challenges that must be addressed to develop these electrochemical reduction processes at a larger, commercialized scale.

In 2015 all the United Nations (UN) member states adopted 17 sustainable development goals (UN-SDG) as part of the 2030 Agenda, which is a 15-year plan to meet ambitious targets to eradicate poverty, protect the environment, and improve the quality of life around the world. Although the global community has progressed, the pace of implementation must accelerate to reach the UN-SDG time-line. For this to happen, professionals, institutions, companies, governments and the general public must become cognizant of the challenges that our world faces and the potential technological solutions at hand, including those provided by chemical engineering. Process intensification (PI) is a recent engineering approach with demonstrated potential to significantly improve process efficiency and safety while reducing cost. It offers opportunities for attaining the UN-SDG goals in a cost-effective and timely manner. However, the pedagogical tools to educate undergraduate, graduate students, and professionals active in the field of PI lack clarity and focus. This paper sets out the state-of-the-art, main discussion points and guidelines for enhanced PI teaching, deliberated by experts in PI with either an academic or industrial background, as well as representatives from government and specialists in pedagogy gathered at the Lorentz Center (Leiden, The Netherlands) in June 2019 with the aim of uniting the efforts on education in PI and produce guidelines. In this Part 1, we discuss the societal and industrial needs for an educational strategy in the framework of PI. The terminology and background information on PI, related to educational implementation in industry and academia, are provided as a preamble to Part 2, which presents practical examples that will help educating about the potential of Process Intensification.

The present work focusses on measuring the permeability across gas diffusion layers (GDLs) first in a dedicated cell and later in PEM fuel cell configuration with varying bi-polar plate designs. Eight carbon paper-based GDLs with and without the microporous layer (MPL), have been tested. An in-house designed dedicated cell allowed measuring pressure drop depending on flow rate, for i) through-plane and ii) in-plane direction. Further, transport measurements were conducted in 25 cm2 bi-polar plates (BPs) in fuel cell configuration having single or multiple serpentine channels, by stacking the GDL inside. The results show that gas permeability in the dedicated cell for through-plane and in-plane can be estimated by using Darcy's law. However, for BPs, the flow is affected additionally by inertial contribution (Darcy-Forchheimer). Finally, the efficiency allowed by selected GDLs installed in a fuel cell under operation shows a relationship between the equivalent permeability and the fuel cell performance.

Mass transfer phenomena in membrane fuel cells are complex and diversified because of the presence of complex transport pathways including porous media of very different pore sizes and possible formation of liquid water. Electrochemical impedance spectroscopy, although allowing valuable information on ohmic phenomena, charge transfer and mass transfer phenomena, may nevertheless appear insufficient below 1 Hz. Use of another variable, that is, back pressure, as an excitation variable for electrochemical pressure impedance spectroscopy is shown here a promising tool for investigations and diagnosis of fuel cells.

Designing and manufacturing multifunctional nanoparticles (NPs) are of considerable interest for both academic and industrial research. Among NPs used in this field, iron oxide NPs show low toxicity compared to metallic ones and are thus of high interest for biomedical applications. In this work, superparamagnetic Fe3−δO4-based core/shell NPs were successfully prepared and characterized by the combination of different techniques, and their physical properties were investigated. We demonstrate the efficiency of the layer-by-layer process to graft polyelectrolytes on the surface of iron oxide NPs. The influence of the polyelectrolyte chain configuration on the magnetic properties of the Fe3−δO4/polymer core/shell NPs was enlightened. The simple and fast process described in this work is efficient for the grafting of polyelectrolytes from surfaces, and thus, derived Fe3−δO4 NPs display both the physical properties of the core and of the macromolecular shell. Finally, the cytotoxicity toward the human THP-1 monocytic cell line of the core/shell NPs was assessed. The results showed that the polymer-capped Fe3−δO4 NPs exhibited almost no toxicity after 24 h of exposure at concentrations up to 25 μg mL–1. Our results show that these smart superparamagnetic nanocarriers with stealth properties are promising for applications in multimodal cancer therapy, including drug delivery.

The term “Industry 4.0″, which refers to a fourth industrial revolution, is a recent neologism. The rise of digital technology including, artificial intelligence, the Internet of things and networks, “smart” and responsive devices, etc … is more and more omnipresent. In solving the related challenges of Industry 4.0, it is necessary to improve the involvement and training of employers and employees. This is particularly true for their education in process safety. Two surveys were submitted to the relevant stakeholders. Their results showed absence of industry 4.0 topics in the current courses on process safety. On the other hand, a review of the master's degree programs available in Europe revealed the recent emergence of new highly specialized courses in some of the topics of industry 4.0. The definition of “Safety 4.0″ leads to recommend two potential global training pathways, with one corresponding to the requirements of Industry 4.0 & Safety 4.0 intersections, recommended within the framework of pedagogical taxonomy models.

International audience; A side effect of high level waste vitrification at 1100°C is the volatilization of radioactive cesium (Cs), recaptured further on in the process as a solid aerosol by a dust scrubber. Feedback from industry suggests that Cs combines with technetium (Tc) █ simulated here by rhenium (Re), chosen for its similar behavior █ to form volatile species. This work characterized Cs volatilization and aerosol formation. The first experiment involved elaborating and analyzing a simplified glass enriched with Cs and Re, which reinforce the volatilization phenomena. The results showed that a demixed liquid phase rich in Cs, Re, Mo, and Na formed in the liquid melt, which is reminiscent of a molybdic phase evoked in the literature. Moreover, analyzing the condensed gases led to the conclusion that the alkalis and Re volatilize congruently at around 700°C. In the second experiment, a series of measurements of the gas phase characterized aerosols throughout the process. The size distribution results showed that the particles formed in the furnace were mostly submicronic, and that the aerosols in the calciner and the dust scrubber included nanoparticles and micronic particles. SEM-EDS characterization revealed the composition of a spherical particle from the furnace made of two nested phases: one rich in Cs-Re-O, and the other rich in Na-Mo-O. The analyses performed showed that Cs and Re could be found in every particle sampled throughout the process, and that the micronic particles might originate from the aggregation of submicronic particles because of composition similarities. Thus, the observations led to a better understanding of the behavior of the elements of interest in both the melt and the gas phase.

International audience; The phase behavior of the CO2 (1) + 2,3-dimethylbutane (2) binary mixture has been experimentally studied between 293 and 373 K. Saturation pressures, ranging from 14.0 to 112.2 bar, were visually measured using a high-pressure cell at carbon dioxide mole fractions between 0.20 and 0.93.78 experimental points have been measured: 67 bubble points and 11 dew points. Experimental results reveal that the vapor-liquid critical locus is a continuous curve between the two pure compounds, meaning that the studied binary system exhibits a type I or II phase behavior in the classification scheme of Van Konynenburg and Scott. The experimental data can be very satisfactorily represented by the Peng-Robinson equation of state with mixing rules that embed a temperature-dependent binary interaction parameter.

Lignin liquefaction microkinetics is a move toward a more first-principles (i.e., ab initio)-based understanding at the molecular level in reaction engineering. While the microkinetic modeling of r...

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International audience; Nickel recovery by agromining has been widely studied because of the abundance of species that hyperaccumulate this element. But at the same time, in the context of the circular economy, there is growing interest in recovery of other elements for both economic and environmental reasons. Firstly, the recovery of gold from mine tailings appears increasingly promising, as does that of rare earth elements, which are strategic for numerous advanced technologies. In both cases, the economic value is a driver but also a need to remediate mine tailing by nature-based solutions. Secondly, despite being less valuable, the recovery of Cd and Zn has been much studied, because these two elements are contaminants of many industrial or agricultural soils and many plants are capable of accumulating them. It is therefore essential to find solutions for disposal of the biomass contaminated with metals and preferably by profiting from it. For this set of elements, processes based on thermal or chemical methods have been proposed on a small scale and some are on the verge of being scaled up. Other elements, such as metals of the platinoid family, Mn or molecules of pharmaceutical interest, have been the subject of pioneering work that remains to be developed. At the present time, it can be considered that in this area there is still a world to explore.

Titanium-based metal-organic framework (Ti-MOF) is part of the MOF family and has attracted much interest for its unique structural features. Some Ti-based MOFs are difficult to crystallize during the synthesis process; hence only limited studies have been reported. Moreover, the fundamental of Ti-MOF has received less attention, which is crucial to the provision of scientific information for customizing Ti-MOF with suitable properties for practical applications. Thus, this review highlights the Ti-based MOF structure and subsequently summarizes the discovery and development of ever-emerging MIL-125 as advanced materials with multifunctional properties. MIL-125 is a Ti-based MOF derived from Ti metal ions and carboxylate organic ligands. Different modification strategies have been outlined, such as functionalizing with ligands, modifying with metal ions, or incorporating other materials. The versatility and flexibility of MIL-125 elevate its prospects in photocatalytic applications, such as photodegradation of water pollutants, water splitting, and photoreduction of CO2. Finally, the future perspectives were presented at the end of this review to provide beneficial information aiming to expand the capability of MIL-125 in advanced chemistry and materials.

International audience; Three complementary Kraft lignins and a Soda lignin were characterized by NMR (31P, 13C, and HSQC) and GPC. Their theoretical yield in monomers (TMY) assuming a complete cleavage of all β-O-4 linkages was calculated based on these analyses. The most recalcitrant Kraft lignin according to the TMY criteria was depolymerized in supercritical ethanol (250 °C, H2, 110 bar) with Pt/C, Ni/C, and Ru/C catalysts. All catalysts present an important effect on monomers (analyzed by GC/MS), oligomers (by UV fluorescence), and char yields. They promote cracking reactions and the stabilization of the broken bonds by H-transfers. The hydrogenation of the side chains of the monomers is also promoted to notably produce propyl-guaiacol. We show that an oligomeric pool prevails for all catalysts. Then, the effect of lignin structure on the depolymerization mechanism was studied by comparing the 4 lignins with the least precious catalyst (Ni/C). The S/G ratio of monomers is well related to the S/G ratio of lignins. Under our conditions, the β-O-4 content and the TMY do not control the yields in monomers. They are not relevant indicators for the depolymerization of these recalcitrant technical lignins. Future work should focus on novel catalysts and processes to improve the selective conversion of C–C bonds if monomers remain the targeted product.

International audience; Computation‐based techniques and modelling of human knowledge and preferences by using multi‐criteria decision aid (MCDA) methods are integrated in a multi‐scale and multi‐disciplinary approach for the chemical product and process design. The proposed methodology has four main stages: (a) construction of a molecular model for predicting product performance, (b) validation of product performance, (c) selection of alternatives integrating preferences of manufacturers and consumers, and (d) process optimization implementing MCDA methods. The methodology is oriented to find new products that can replace components of formulations, whose performance is already known. It was applied to an exploratory study about the use of glycerol as raw material to produce plasticizers for polyvinyl chloride (PVC), replacing 2‐ethylhexyl phthalate (DEHP). The results of the case study and the proposed process design offer promising prospects regarding their application in other chemical products.

International audience; In this work, the influence of the stoichiometry of LaxFeOy films on their activity for H2 production by photoelectrochemical (PEC) water splitting was investigated. Thin LaxFeOy films were deposited on electrodes by magnetron co-sputtering and their composition was controlled by adjusting the power applied on metallic iron and lanthanum targets. The highest photoactivity was observed for La0.43FeOy films. The crystallization of these films and their photocatalytic activity were further improved by oxidation in an external furnace at 650 °C for 2 h. Transmission electron microscopy (TEM) analyses confirm the formation of LaFeO3 crystallites in the film and show a thin continuous polycrystalline Fe2O3 layer at the surface. The presence of Fe2O3 at the upper surface originates from an exsolution mechanism typically observed for non-stoichiometric perovskites. The improvement of the photocatalytic properties by adjusting the stoichiometry, the oxidation temperature and the film thickness was confirmed by H2 production measurements performed by mass spectrometry. We observe a large increase in H2 production rate (103%) by comparison with a stoichiometric LaFeO3 thin film. The improvement in catalytic performances for these non-stoichiometric films composed of earth abundant, low-cost and non-toxic elements, make them of high interest materials for photoelectrodes in PEC water splitting systems.

International audience

Membrane contactors offer promising performances for the intensification of gas liquid absorption processes. Impressive volume reduction factors compared to packed columns have been reported, mostly for absorption in chemical solvents (e.g. CO2 post combustion capture with MEA). A very limited number of studies addressed however the potentialities of membrane contactors for physical absorption processes. Moreover, the interplay between volume reduction and energy requirement, which is expected to be of major importance for physical solvents, is unexplored. In this study, a systematic parametric analysis of the intensification and specific energy requirement of membrane contactors for CO2 absorption in 5 different physical solvents is reported. The best flow configuration, module packing fraction and membrane properties (mass transfer performances) are identified for the different solvents. Very high intensification factors compared to the baseline technology (i.e. packed column) are shown to be potentially achievable.

International audience

The rigorous description of adsorption isotherms of gases or vapors on solids is of major interest for analytical methods such as chromatography and adsorbent-based separation processes (e.g., PSA)...

The VOC removal from air is a major concern both in the context of occupational and domestic exposure. Membrane processes are often presented as unsuitable for the removal of low concentrated VOCs mainly due to a too low driving force leading to high-energy costs. The aim of the work presented in this paper is to investigate the original combination of a dense membrane separation process and a photocatalytic oxidation process implemented in the permeate compartment of the system for the intensification of the separation and the decomposition of toxic compounds. An unpublished modeling of this coupled processes completed by a robust experimental study integrating the main operating parameters (flow rates, pressures, membrane materials, catalyst mass, concentration, light irradiance) is presented in this work. This exploratory study shows that for a test compound, n-hexane, this approach significantly intensifies the separation of a low-concentration VOC (i.e. 1 to 25 ppm) with a low-energy cost. The model developed here allows designing more enhanced system such as hybrid plug-flow module operating with a thin polydimethylsiloxane membrane and sweep-gas on the permeate compartment. This configuration seems particularly relevant for an efficient VOC separation and limits greatly the presence of potential by-products in the treated effluent, such as formaldehyde, acetaldehyde or carbon monoxide well-known intermediates identified in photocatalysis. From a reaction position, this hybrid process leads to the VOC photocatalytic oxidation advantageously increased compared to a single plug-flow reactor especially for low light irradiances (≈3 W m−2). This process is suitable to work with the solar irradiance.

Carbon monoliths were tested as electrodes for vanadium redox batteries. The materials were synthesised by a hard-templating route, employing sucrose as carbon precursor and sodium chloride crystals as the hard template. For the preparation process, both sucrose and sodium chloride were ball-milled together and molten into a paste which was hot-pressed to achieve polycondensation of sucrose into a hard monolith. The resultant material was pyrolysed in nitrogen at 750 ◦C, and then washed to remove the salt by dissolving it in water. Once the porosity was opened, a second pyrolysis step at 900 ◦C was performed for the complete conversion of the materials into carbon. The products were next characterised in terms of textural properties and composition. Changes in porosity, obtained by varying the proportions of sucrose to sodium chloride in the initial mixture, were correlated with the electrochemical performances of the samples, and a good agreement between capacitive response and microporosity was indeed observed highlighted by an increase in the cyclic voltammetry curve area when the SBET increased. In contrast, the reversibility of vanadium redox reactions measured as a function of the difference between reduction and oxidation potentials was correlated with the accessibility of the active vanadium species to the carbon surface, i.e., was correlated with the macroporosity. The latter was a critical parameter for understanding the differences of energy and voltage efficiencies among the materials, those with larger macropore volumes having the higher efficiencies. This work was supported by ICEEL and Region Grand Est and J.F.V.-V. was hired with these fundings. This work was partly supported by a grant overseen by the French National Research Agency (Pc2TES ANR-16-CE06-0012-01), and the authors involved in it (AC, BK and VF) acknowledge the support of the project's coordinator, Mrs Fouzia Achchaq. This study was partly supported by TALiSMAN project (2019-000214), funded by European Regional Development Fund (ERDF).

The relationship between interfacial and bulk emulsion viscoelasticity is investigated. Water-in-dodecane reverse Pickering emulsions, with a dispersed phase volume fraction of 0.66, stabilized with partially hydrophobic silica particles are addressed. Interfacial and bulk viscoelastic properties are probed via 2D and 3D oscillatory shear rheology. The silica particles concentration and NaCl content have been varied. In the whole range of concentrations studied the elastic modulus (G′) remains always greater than the viscous modulus for 2D and 3D rheology. The viscoelastic behavior can be related to the silica concentration both at the interface and in the emulsion. Power law dependences towards the silica content are recorded for the interfacial and the bulk emulsion elastic modulus. When increasing the NaCl concentration, the viscoelastic properties both at the interface and in the emulsion become stronger. The amount of silica and NaCl produces similar effects on both the interface and bulk viscoelastic properties. The increase of their concentration induces a rigidification of the dodecane/water interface since G P ′ (interface) increases. Such interfacial hardening produces a rigidification of the droplets ( G P ′ (Emulsion) is enhanced). Correlations between the interfacial and bulk emulsion viscoelasticity are also extracted from the experimental data. This is the first time that these kinds of relationship are reported. These results highlight that everything that affects the interfacial viscoelasticity is reflected on the bulk scale of emulsions.

International audience; Correlation of the mass transfer characteristics of microfluidic parallel-plate electrochemical reactors is proposed for the first time. Firstly, the variation in the mass transfer coefficient (k m) (1.61-3.94 × 10 − 5 m s − 1) over a wide range of interelectrode distances (d elec) from millimetric (3 mm) to micrometric values (100 µm) is reported. Secondly, a drastic slope change in the curve makes it possible to identify the onset of microfluidic behavior in a quantitative way for the first time, i.e. below a 1000 µm gap. Thirdly, a mathematical model is proposed which predicts k m for any d elec of interest. Fourthly, under laminar flow (7 < Reynolds (Re) < 623) and for temperatures in the range of 10-50 • C (532 < Schmidt (Sc) < 3315), new Sherwood (Sh) correlations are obtained for both microfluidic and millimetric configurations. It is thus feasible to extrapolate k m for microfluidic electrochemical reactor scale-up.

Cancer is the second leading cause of death worldwide after cardiovascular disease. Depending on the type and the location of the tumor, several cancer treatments are implemented. Among these, the three most conventional therapies are surgery, radiotherapy and chemotherapy. However, there are other therapeutic approaches such as photodynamic therapy (PDT). PDT relies on the combined action of light, a photoactivable molecule called photosensitizer (PS) and molecular oxygen. Most of the PSs used for clinical applications are not cancer-cell specific. One of the solutions to overcome this problem is the use of nanoparticles (NPs) to induce a passive targeting. It is also possible to graft a vector onto the NPs to specifically target membrane receptors overexpressed in the tumor cells or neovessels surrounding the tumor. In this review, we focus on the NPs loaded with PSs and coupled to peptides for targeted PDT. We described nanosystems that targeted Neuropilin-1 (NRP-1), αvβ3 integrins, nucleolin membrane receptor, epidermal growth factor (EGF) receptor, protein-glutamine-gamma-glutamyltransferase (TGM2), p32, transferrin, PD-1, and mitochondrial membrane. The use of a cell absorbing-peptide is also described.