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In this paper, the molecular dynamics of a series of ester derivatives of ibuprofen (IBU), in which the hydrogen atom from the hydroxyl group was substituted by the methyl, isopropyl, hexyl, and benzyl moieties, has been investigated using Broadband dielectric (BD), Nuclear magnetic resonance (NMR), and Raman spectroscopies. We found that except for benzyl IBU (Ben-IBU), an additional process (slow mode, SM) appears in dielectric spectra in all examined compounds. It is worth noting that this relaxation process was observed for the first time in non-modified IBU (a Debye relaxation). According to suggestions by Affouard and Correia [J. Phys. Chem. B. 114, 11397 (2010)] as well as further studies by Adrjanowicz et al. [J. Chem. Phys. 139, 111103 (2013)] on Met-IBU, it was attributed to synperiplanar–antiperiplanar conformational changes within the molecule. Herein, we have shown that with an increasing molecular weight of the substituent, the relaxation times of the SM become longer and its activation energy significantly increases. Moreover, this new relaxation mode was found to be broader than a simple Debye relaxation in Iso-IBU and Hex-IBU. Additional complementary NMR studies indicated that either there is a significant slowdown of the rotation around the O=C—O—R moiety or this kind of movement is completely suppressed in the case of Ben-IBU. Therefore, the SM is not observed in the dielectric loss spectra of this compound. Finally, we carried out isothermal experiments on the samples which have a different thermal history. Interestingly, it turned out that the relaxation times of the structural processes are slightly shorter with respect to those obtained from temperature dependent measurements. This effect was the most prominent in the case of Hex-IBU, while for Ben-IBU, it was not observed at all. Additional time-dependent measurements revealed the ongoing equilibration manifested by the continuous shift of the structural process, until it finally reached its equilibrium position. Further Raman investigations showed that this effect may be related to the rotational/conformational equilibration of the long hexyl chains. Our results are the first ones demonstrating that the structural process is sensitive to the conformational equilibration occurring in the specific highly viscous systems. [ABSTRACT FROM AUTHOR]

This work thoroughly investigates chemical solvent-particles interactions during the formation of composite particles by pulsed laser melting of α-Fe2O3. Two solvents, with different dielectric constants, such as ethyl acetate (εr = 6) and ethanol (εr = 24.6), were examined in terms of their effect on the morphology, size, and phase composition of iron oxide composites. We calculated the laser fluence curves using the heating-melting-evaporation approach to identify the critical particle size that undergoes the phase changes first. We assessed the temperature of the particles irradiated with 390 mJ/pulse.cm2 in both solvents, including the heat dissipation between the particles and the liquid. The phase diagram of the Fe–O–C–H system was calculated to determine the temperature–pressure relationship of the system in equilibrium. We also employed an in situ GC–MS analysis to identify the volatile products during irradiation. Based on our experimental results, we concluded that the final diameter of the composites increases from 400 to 600 nm, along with the decreasing dielectric constant of the solvent, which is related to the different polarization of the organic liquid and the degree of particle agglomeration. The reduction of hematite in ethanol proceeded much faster, ending up with Fe/FeCx, while in ethyl acetate, it ended up with Fe3O4. Among all the particles, those with a diameter of 200 nm have the highest temperature and undergo the phase transition first. The temperature of a 200 nm composite particle in ethanol is slightly lower than in ethyl acetate, i.e. 1870 K as compared to 1902 K. Phase equilibrium diagrams proved the existence of Fe, FeO, and Fe3O4 as the preferred phases at about 1900 K. Our research provides a new insight into the process of submicron particle formation during pulsed laser irradiation and allows proposing a mechanism for the growth of particles of different size and phase composition depending on the solvent. [ABSTRACT FROM AUTHOR]

The comparison between NiFe2O4 (co-precipitation) and NiFe2O4@SiO2 (co-precipitation and microemulsion) ferrite nanoparticles in their as-received and annealed form is presented. The structural characterization revealed the gradual crystallization of as-received samples induced by thermal treatment. The existence of cubic inverse spinel ferrite structure with tetrahedral and octahedral iron occupancy is confirmed in all samples by the comprehensive study. The Fourier-transform infrared (FTIR) spectroscopy confirmed the typical spinel structure and other Fe-based states, whereas the presence of nonstoichiometric hematite is detected in the annealed NiFe2O4 sample. In the case of nanoparticles embedded into the silica matrix, the crystallization of initially amorphous silica is revealed in structural and microstructural characterization. As shown by FTIR, the applied thermal treatment reduces the water molecules and hydroxyl units compared to the initial material. The separation of the rhombohedral hematite α-Fe2O3 phase in the NiFe2O4 ferrite evidenced during the annealing process is demonstrated in structural and magnetic studies. The analysis of saturation magnetization pointed to the spin canting phenomenon in the surface layer with a slight change of the so-called dead layer upon heating. The room temperature superparamagnetic state (SPM) is modified in the NiFe2O4 sample across annealing as an effect of ferrite crystallization and grain growth as well as hematite separation. For as-received NiFe2O4, with temperature decrease, the blocking process preceded by the freezing process is observed. The silica shell is recognized as the sustaining cover for the SPM state. The electronic structure studies confirmed the complex nature of the Fe-based states. [ABSTRACT FROM AUTHOR]

In this paper, we present results of dielectric and shear-mechanical studies for amine (2-ethyl-1-hexylamine) and thiol (2-ethyl-1-hexanethiol) derivatives of the monohydroxy alcohol, 2-ethyl-1-hexanol. The amine and thiol can form hydrogen bonds weaker in strength than those of the alcohol. The combination of dielectric and shear-mechanical data enables us to reveal the presence of a relaxation mode slower than the a-relaxation. This mode is analogous to the Debye mode seen in monohydroxy alcohols and demonstrates that supramolecular structures are present for systems with lower hydrogen bonding strength. We report some key features accompanying the decrease in the strength of the hydrogen bonding interactions on the relaxation dynamics close to the glass-transition. This includes changes (i) in the amplitude of the Debye and a-relaxations and (ii) the separation between primary and secondary modes. [ABSTRACT FROM AUTHOR]

Fossil bone cells (osteocytes) are known mainly from the shape-casting vacuities they leave behind after cell decay; however, they may occasionally be preserved as three-dimensionally fossilized soft parts. Here we present brownish to rust-coloured microbodies, extracted from a Middle Triassic (ca. 245 Ma) bone of the reptile Nothosaurus, which are morphologically consistent with bone cells of present-day vertebrates. In situ imaging shows that these structures, which are reminiscent of bone cells, are harboured in lacunae framed by the bone matrix. Chemical characterization using energy-dispersive X-ray, Raman, and X-ray photoelectron spectroscopy revealed the presence of various phases of iron oxide mineralization. The predominant mineral phases are hematite and goethite; magnetite and maghemite appear to occur sporadically. It is not clear how these nanograined mineral phases were formed. Most likely mineralization proceeded very early and was triggered by local microenvironmental conditions favouring the precipitation of iron phases. The absence of a distinct signal indicating organic molecules suggests that the original bone cells underwent autolysis or other degradative processes before or during mineralization. [ABSTRACT FROM AUTHOR]

Comprehensive FTIR studies on the progress of mutarotation in d-fructose mixed with maltitol have been carried out over a wide range of temperatures, both above and below the glass transition temperature Tg. In addition to the analysis of single bands, we have developed a completely new approach considering the full spectral range to follow the overall progress of the reaction. We have found that at the calorimetric Tg, there is a clear change in the temperature dependence of constant rates. The activation barrier for mutarotation changes from around 59 kJ mol−1 (the supercooled state) to around 249 kJ mol−1 (the glassy state). This dramatic variation in the activation barrier is consistent with the change in the mechanism of this specific chemical conversion, as theoretically considered by Wlodarczyk et al. [Phys. Chem. Chem. Phys., 2014, 16, 4694–4698]. Alternatively, it can also be connected to the change in the viscosity of the sample. Additionally, we investigated the relationship between constant rates (k) of mutarotation, structural relaxation times (τα), and dc conductivity (σdc) above and below the glass transition temperature. It was found that there was a linear correlation between all these quantities; they scale with various exponents changing at Tg. Our results also indicate that a single activation barrier might not be sufficient to describe the mutarotation process. [ABSTRACT FROM AUTHOR]

The NiTi shape memory alloy was covered with chitosan/silver layer. Coatings were deposited at room temperature using combination of processing parameters such as deposition voltage and amount of silver in colloidal suspension. Structure of layers was studied by means of X-ray diffraction. Quality of the coatings was evaluated basing on observations done in scanning electron microscopy. Transformation behaviour of coated samples was studied with use of differential scanning calorimeter. The covered sample revealed presence of the reversible martensitic transformation and ability to deformation (in bending mode) up to 8%. Forward martensitic transformation, in as-received NiTi alloy and in alloy after layer deposition occurred in two steps B2-R-B19’. After deformation quality of the chitosan/silver layer remained unchanged.

This work thoroughly investigates chemical solvent-particles interactions during the formation of composite particles by pulsed laser melting of α-Fe2O3. Two solvents, with different dielectric constants, such as ethyl acetate (εr = 6) and ethanol (εr = 24.6), were examined in terms of their effect on the morphology, size, and phase composition of iron oxide composites. We calculated the laser fluence curves using the heating-melting-evaporation approach to identify the critical particle size that undergoes the phase changes first. We assessed the temperature of the particles irradiated with 390 mJ/pulse.cm2 in both solvents, including the heat dissipation between the particles and the liquid. The phase diagram of the Fe–O–C–H system was calculated to determine the temperature–pressure relationship of the system in equilibrium. We also employed an in situ GC–MS analysis to identify the volatile products during irradiation. Based on our experimental results, we concluded that the final diameter of the composites increases from 400 to 600 nm, along with the decreasing dielectric constant of the solvent, which is related to the different polarization of the organic liquid and the degree of particle agglomeration. The reduction of hematite in ethanol proceeded much faster, ending up with Fe/FeCx, while in ethyl acetate, it ended up with Fe3O4. Among all the particles, those with a diameter of 200 nm have the highest temperature and undergo the phase transition first. The temperature of a 200 nm composite particle in ethanol is slightly lower than in ethyl acetate, i.e. 1870 K as compared to 1902 K. Phase equilibrium diagrams proved the existence of Fe, FeO, and Fe3O4 as the preferred phases at about 1900 K. Our research provides a new insight into the process of submicron particle formation during pulsed laser irradiation and allows proposing a mechanism for the growth of particles of different size and phase composition depending on the solvent. [ABSTRACT FROM AUTHOR]

A detailed examination of the altered silicate-carbonate xenolith embedded within the ignimbrite of the Upper Chegem Caldera revealed a new occurrence of a rare carbonate mineral known as defernite, with chemical formula Ca 6 [(CO 3 ) 2-x (Si 2 O 7 ) x/2 ](OH) 7 [Cl 1-x (H 2 O) x ], where x ≈ 0.4. Defernite crystallizes as colorless to white fibrous aggregates, reaching 100-150 μm diameters. Subsequently, Raman investigations of defernite from the Upper Chegem Caldera were conducted to perform a comprehensive structural analysis and compare it with minerals found in other locations. During this examination, band assignments focused on the carbonate ion vibration (CO 3 2- ) with a band at 1085 cm -1 and the hydroxyl group, characterized by a series of strong bands around 3590-3600 cm -1 , particularly evident in oriented crystals along the (010) plane. Experimentation involving the alteration of incident laser light polarization highlighted a reduction in the intensity of carbonate and hydroxyl-related bands and the activation of a band around 3390 cm -1 . This phenomenon is explained by the formation of hydrogen bonding between hydroxyl groups and chlorine or molecular water, potentially occupying chlorine positions. Lastly, a temperature-dependent experiment demonstrated the instability of the 3390 cm -1 band, which dissipated with increasing temperature. This insight explains the band's origin around 3590 cm -1 , ascribed to non-degenerate hydroxyl groups as a key marker within the defernite structure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Molecular dynamics and transport coefficients change significantly around the so-called Arrhenius crossover in glass-forming systems. In this article, we revisit the dynamic processes occurring in a glass-forming macrocyclic crown thiaether MeBzS 2 O above its glass transition, revealing two crossover temperatures: T B at 309 and T A at 333 K. We identify the second one as the Arrhenius crossover that is closely related to the normal-to-supercooled liquid transition in this compound. We show that the transformation occurring at this point goes far beyond molecular dynamics (where the temperature dependence of structural relaxation times changes its character from activation-like to super-Arrhenius), being reflected also in the internal structure and diffraction pattern. In this respect, we found a twofold local organization of the nearest-neighbor molecules via weak van der Waals forces, without the formation of any medium-range order or mesophases. The nearest surrounding of each molecule evolves structurally in time due to the ongoing fast conformational changes. We identify several conformers of MeBzS 2 O , demonstrating that its lowest-energy conformation is preferred mainly at lower temperatures, i.e., in the supercooled liquid state. Its increased prevalence modifies locally the short-range intermolecular order and promotes vitrification. Consequently, we indicate that the Arrhenius transition is fuelled rather by conformational changes in this glass-forming macrocyclic crown thiaether, which is a different scenario from the so-far existing concepts. Our studies combine broadband dielectric spectroscopy (BDS), X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, molecular dynamics (MD) simulations, and density functional theory (DFT) calculations.

Although the antimicrobial activity of nanoparticles (NPs) penetrating inside the cell is widely recognised, the toxicity of large NPs (>10 nm) that cannot be translocated across bacterial membranes remains unclear. Therefore, this study was performed to elucidate the direct effects of Ag-NPs, Cu-NPs, ZnO-NPs and TiO 2 -NPs on relative membrane potential, permeability, hydrophobicity, structural changes within chemical compounds at the molecular level and the distribution of NPs on the surfaces of the bacteria Bacillus cereus and Staphylococcus epidermidis. Overall analysis of the results indicated the different impacts of individual NPs on the measured parameters in both strains depending on their type and concentration. B. cereus proved to be more resistant to the action of NPs than S. epidermidis. Generally, Cu-NPs showed the most substantial toxic effect on both strains; however, Ag-NPs exhibited negligible toxicity. All NPs had a strong affinity for cell surfaces and showed strain-dependent characteristic dispersion. ATR-FTIR analysis explained the distinctive interactions of NPs with bacterial functional groups, leading to macromolecular structural modifications. The results presented provide new and solid evidence for the current understanding of the interactions of metallic NPs with bacterial membranes., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Oliwa Metryka reports financial support was provided by National Science Centre, Poland. Oliwia Metryka reports a relationship with National Science Centre Poland that includes: funding grants. Oliwia Metryka has patent licensed to CC-BY public copyright licence. The Authors declare no conflict of interest. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Despite decades of studies, a clear understanding of near- T g phenomena remains challenging for glass-forming systems. This review delves into the intricate molecular dynamics of the small, heterocyclic thioether, 6-methyl-2,3-dihydro-1,4-benzodithiine (MeBzS 2 ), with a particular focus on its near- T g cold crystallization and relaxation mechanisms. Investigating isothermal crystallization kinetics at various temperatures reveals a significant interplay between its molecular dynamics and recrystallization from a supercooled liquid. We also identify two independent interconversion paths between energetically privileged conformers, characterized by strained transition states. We demonstrate that these spatial transformations induce substantial alterations in the dipole moment orientation and magnitude. Our investigation also extends to the complex salt PdCl 2 (MeBzS 2 ), where we observe the transient conformers directly, revealing a direct relationship between their abundance and the local or macroscopic electric field. The initially energetically privileged isomers in an undisturbed system become less favored in the presence of an external electric field or ions, resulting even in an unexpected inversion of states. Consequently, we confirm the intramolecular character of secondary relaxation in MeBzS 2 and its mechanism related to conformational changes within the heterocyclic ring. The research is based on the combination of broadband dielectric spectroscopy, X-ray diffraction, and quantum density functional theory calculations.

In response to the persistent challenge of heavy and noble metal environmental contamination, our research explores a new idea to capture silver through porous spherical silica nanostructures. The aim was realized using microwave radiation at varying power (P = 150 or 800 W) and exposure times (t = 60 or 150 s). It led to the development of a silica surface with enhanced metal-capture capacity. The microwave-assisted silica surface modification influences the notable changes within the carrier but also enforces the crystallization process of silver nanoparticles with different morphology, structure, and chemical composition. Microwave treatment can also stimulate the formation of core-shell bioactive Ag/Ag 2 CO 3 heterojunctions. Due to the silver nanoparticles' sphericity and silver carbonate's presence, the modified nanocomposites exhibited heightened toxicity against common microorganisms, such as E. coli and S. epidermidis . Toxicological assessments, including minimum inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC 50 ) determinations, underscored the efficacy of the nanocomposites. This research represents a significant stride in addressing pollution challenges. It shows the potential of microwave-modified silicas in the fight against environmental contamination. Microwave engineering underscores a sophisticated approach to pollution remediation and emphasizes the pivotal role of nanotechnology in shaping sustainable solutions for environmental stewardship.

The objective of this research was to develop a surface modification for the NiTi shape memory alloy, thereby enabling its long-term application in implant medicine. This was achieved through the creation of innovative multifunctional hybrid layers comprising a nanometric molecular system of silver-rutile (Ag-TiO 2 ), known for its antibacterial properties, in conjunction with bioactive submicro- and nanosized hydroxyapatite (HAp). The multifunctional, continuous, crack-free coatings were produced using the electrophoretic deposition method (EPD) at 20 V/1 min. Structural and morphological analyses through Raman spectrometry and scanning electron microscopy (SEM) provided comprehensive insights into the obtained coating. The silver within the layer existed in the form of nanometric silver carbonates (Ag 2 CO 3 ) and metallic nanosilver. Based on DTA/TG results, dilatometric measurements, and high-temperature microscopy, the heat treatment temperature for the deposited layers was set at 800 °C for 2 h. The procedures applied resulted in the creation of a new generation of materials with a distinct structure compared with the initial nanopowders. The resulting composite layer, measuring 2 μm in thickness, comprised hydroxyapatite (HAp), apatite carbonate (CHAp), metallic silver, silver oxides, Ag@C, and rutile exhibiting a defective structure. This structural characteristic contributes significantly to its heightened activity, influencing both bioactivity and biocompatibility properties.

This article presents the synthesis and molecular dynamics investigation of three novel cyclic thioethers: 2,3-(4'-methylbenzo)-1,4,7,10-tetrathiacyclododeca-2-ene (compound 1 ), 2,3,14,15-bis(4',4″(5″)-methylbenzo)-1,4,7,10,13,16,19,22,25-octathiacyclotetracosa-2,14-diene (compound 2 ), and 2,3,8,9-bis(4',4″(5″)-methylbenzo)-1,4,7,10-tetrathiacyclododeca-2,8-diene (compound 3 ). The compounds exhibit relatively high glass transition temperatures ( T g ), which range between 254 and 283 K. This characteristic positions them within the so-far limited category of crown-like glass-formers. We demonstrate that cyclic thioethers may span both the realms of ordinary and sizeable molecular glass-formers, each featuring distinct physical properties. Furthermore, we show that the T g follows a sublinear power law as a function of the molar mass within this class of compounds. We also reveal multiple dielectric relaxation processes of the novel cyclic thioethers. Above the T g , their dielectric loss spectra are dominated by a structural relaxation, which originates from the cooperative reorientation of entire molecules and exhibits an excess wing on its high-frequency slope. This feature has been attributed to the Johari-Goldstein (JG) process. Each investigated compound exhibits also at least one intramolecular secondary non-JG relaxation stemming from conformational changes. Their activation energies range from approximately 19 kJ/mol to roughly 40 kJ/mol. Finally, we analyze the high-pressure molecular dynamics of compound 1 , revealing a pressure-induced increase in its T g with a dT g / dp coefficient equal to 197 ± 8 K/GPa.

Nanoformulation should minimise the usage of pesticides and limit their environmental footprint. The risk assessment of two nanopesticides with fungicide captan as an active organic substance and ZnO 35-45 nm or SiO 2 20-30 nm as nanocarriers was evaluated using the non-target soil microorganisms as biomarkers. The first time for that kind of nanopesticides next-generation sequencing (NGS) of bacterial 16 S rRNA and fungal ITS region and metagenomics functional predictions (PICRUST2) was made to study structural and functional biodiversity. During a 100-day microcosm study in soil with pesticide application history, the effect of nanopesticides was compared to pure captan and both nanocarriers. Nanoagrochemicals affected microbial composition, especially Acidobacteria-6 class, and alpha diversity, but the observed effect was generally more substantial for pure captan. As for beta diversity, the negative impact was detected only in response to captan and still observed on day 100. Fungal community in the orchard soil showed only a decrease in phylogenetic diversity in captan set-up since day 30. PICRUST2 analysis confirmed several times lower impact of nanopesticides considering the abundance of functional pathways and genes encoding enzymes. Furthermore, the overall data indicated that using SiO 2 20-30 nm as a nanocarrier speeds up a recovery process compared to ZnO 35-45 nm ., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Recent advances in nanotechnology and development of nanoformulation methods, has enabled the emergence of precision farming - a novel farming method that involves nanopesticides and nanoferilizers. Zinc-oxide nanoparticles serve as a Zn source for plants, but they are also used as nanocarriers for other agents, whereas copper-oxide nanoparticles possess antifungal activity, but in some cases may also serve as a micronutrient providing Cu ions. Excessive application of metal-containing agents leads to their accumulation in soil, where they pose a threat to non-target soil organisms. In this study, soils obtained from the environment were amended with commercial zinc-oxide nanoparticles: Zn-O x NPs (10-30) , and newly-synthesized copper-oxide nanoparticles: Cu-O x NPs (1-10) . Nanoparticles (NPs) in 100 and 1000 mg kg -1 concentrations were added in separate set-ups, representing a soil-microorganism-nanoparticle system in a 60-day laboratory mesocosm experiment. To track environmental footprint of NPs on soil microorganisms, a Phospholipd Fatty Acid biomarker analysis was employed to study microbial community structure, whereas Community-Level Physiological Profiles of bacterial and fungal fractions were measured with Biolog Eco and FF microplates, respectively. The results revealed a prominent and persistent effects exerted by copper-containing nanoparticles on non-target microbial communities. A severe loss of Gram-positive bacteria was observed in conjunction with disturbances in bacterial and fungal CLPPs. These effects persisted till the end of a 60-day experiment, demonstrating detrimental rearrangements in microbial community structure and functions. The effects imposed by zinc-oxide NPs were less pronounced. As persistent changes were observed for newly synthesized Cu-containing NPs, this work stresses the need for obligatory testing of nanoparticle interactions with non-target microbial communities in long-term experiments, especially during the approval procedures of novel nano-substances. It also underlines the role of in-depth physical and chemical studies of NP-containing agents, which may be tweaked to mitigate the unwanted behavior of such substances in the environment and preselect their beneficial characteristics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Extracellular matrices contain fibril-like polymers often organized in parallel arrays. Although their role in morphogenesis has been long recognized, it remains unclear how the subcellular control of fibril synthesis translates into organ shape. We address this question using the Arabidopsis sepal as a model organ. In plants, cell growth is restrained by the cell wall (extracellular matrix). Cellulose microfibrils are the main load-bearing wall component, thought to channel growth perpendicularly to their main orientation. Given the key function of CELLULOSE SYNTHASE INTERACTIVE1 (CSI1) in guidance of cellulose synthesis, we investigate the role of CSI1 in sepal morphogenesis. We observe that sepals from csi1 mutants are shorter, although their newest cellulose microfibrils are more aligned compared to wild-type. Surprisingly, cell growth anisotropy is similar in csi1 and wild-type plants. We resolve this apparent paradox by showing that CSI1 is required for spatial consistency of growth direction across the sepal., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

In the current work, we report on the synthesizing of a series of novel nanocomposite materials obtained by functionalizing the SBA-15 silica matrix with anchored iron phosphonate molecules and the following thermal treatment. The obtained results reveal the formation of a unique amorphic layer of Fe-based compounds on the surface of silica walls of SBA-15 channels as a result of the organic groups' decomposition after moderate thermal treatment. Due to their unique structure, represented in an active Fe-containing amorphous coating spread over a large surface area, these materials are of great interest for their potential applications in fields such as catalysis, adsorption, and non-linear optics. The obtained materials remain amorphous, preserving the SBA-15 mesoporous structure up to temperatures of approximately 800 °C, after which the partial melting of the silica backbone is observed with the simultaneous formation of nanocrystals inside the newly-formed glassy mass. All obtained materials were characterized using such techniques as thermogravimetry, transmission and scanning electron microscopy combined with energy dispersive x-ray spectroscopy mapping, Raman spectroscopy, N 2 sorption analysis, x-ray diffraction, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and SQUID measurements., (Creative Commons Attribution license.)

Heavy metals and other organic pollutants burden the environment, and their removal or neutralization is still inadequate. The great potential for development in this area includes porous, spherical silica nanostructures with a well-developed active surface and open porosity. In this context, we modified the surface of silica spheres using a microwave field (variable power and exposure time) to increase the metal uptake potential and build stable bioactive Ag 2 O/Ag 2 CO 3 heterojunctions. The results showed that the power of the microwave field (P = 150 or 700 W) had a more negligible effect on carrier modification than time (t = 60 or 150 s). The surface-activated and silver-loaded silica carrier features like morphology, structure, and chemical composition correlate with microbial and antioxidant enzyme activity. We demonstrated that the increased sphericity of silver nanoparticles enormously increased toxicity against E. coli , B. cereus , and S. epidermidis . Furthermore, such structures negatively affected the antioxidant defense system of E. coli , B. cereus , and S. epidermidis through the induction of oxidative stress, leading to cell death. The most robust effects were found for nanocomposites in which the carrier was treated for an extended period in a microwave field.

The existence of more than one liquid state in a single-component system remains the most intriguing physical phenomenon. Herein, we explore the effect of cation self-assembly on ion dynamics in the vicinity of liquid-liquid and liquid-glass transition of tetraalkyl phosphonium ([P mmm , n ] + , m = 4, 6; n = 2-14) ionic liquids. We found that nonpolar local domains formed by 14-carbon alkyl chains are crucial in obtaining two supercooled states of different dynamics within a single ionic liquid. Although the nano-ordering, confirmed by Raman spectroscopy, still occurs for shorter alkyl chains ( m = 6, n < 14), it does not bring calorimetric evidence of LLT. Instead, it results in peculiar behavior of ion dynamics near the liquid-glass transition and 20-times smaller size of the dynamic heterogeneity compared to imidazolium ionic liquids. These results represent a crucial step toward understanding the nature of the LLT phenomenon and offer insight into the design of efficient electrolytes based on ionic liquids revealing self-assembly behavior.

To functionalize and improve the biocompatibility of the surface of a medical implant made of NiTi shape memory alloy and used in practice, a clamp, multifunctional layers composed of amorphous TiO 2 interlayer, and a hydroxyapatite coating were produced. Electrophoresis, as an efficient method of surface modification, resulted in the formation of a uniform coating under a voltage of 60 V and deposition time of 30 s over the entire volume of the implant. The applied heat treatment (800 °C/2 h) let toa dense, crack-free, well-adhered HAp coating with a thickness of ca. 1.5 μm. and a high crack resistance to deformation associated with the induction of the shape memory effect in the in the deformation range similar to the real implant work after implantation. Moreover, the obtained coating featured a hydrophilic (CA = 59.4 ± 0.3°) and high biocompatibility.

Investments in the transfer and storage of thermal energy along with renewable energy sources strengthen health and economic infrastructure. These factors intensify energy diversification and the more rapid post-COVID recovery of economies. Ionanofluids (INFs) composed of long multiwalled carbon nanotubes (MWCNTs) rich in sp 2 -hybridized atoms and ionic liquids (ILs) display excellent thermal conductivity enhancement with respect to the pure IL, high thermal stability, and attractive rheology. However, the influence of the morphology, physicochemistry of nanoparticles and the IL-nanostructure interactions on the mechanism of heat transfer and rheological properties of INFs remain unidentified. Here, we show that intertube nanolayer coalescence, supported by 1D geometry assembly, leads to the subzipping of MWCNT bundles and formation of thermal bridges toward 3D networks in the whole INF volume. We identified stable networks of straight and bent MWCNTs separated by a layer of ions at the junctions. We found that the interactions between the ultrasonication-induced breaking nanotubes and the cations were covalent in nature. Furthermore, we found that the ionic layer imposed by close MWCNT surfaces favored enrichment of the cis conformer of the bis(trifluoromethylsulfonyl)imide anion. Our results demonstrate how the molecular perfection of the MWCNT structure with its supramolecular arrangement affects the extraordinary thermal conductivity enhancement of INFs. Thus, we gave the realistic description of the interactions at the IL-CNT interface with its (super)structure and chemistry as well as the molecular structure of the continuous phase. We anticipate our results to be a starting point for more complex studies on the supramolecular zipping mechanism. For example, ionically functionalized MWCNTs toward polyionic systems─of projected and controlled nanolayers─could enable the design of even more efficient heat-transfer fluids and miniaturization of flexible electronics.