Solute Solvent Research Articles

Efficient and facile biphasic pretreatment for corn stover fractionation with comprehensive utilization of cellulose, xylan and lignin.

Developing a mild and efficient pretreatment technique to fully utilize lignocellulosic biomass remains a challenge. In this work, a biphasic system with 2-phenoxyethanol (EPH) organic solvent and phosphotungstic acid (PTA) aqueous solution was employed to pretreat corn stover. The prominent synergistic effect between EPH and PTA was revealed to play a key role in the fractionation of corn stover. The excellent separation efficiency with 88.55 % cellulose retention, 85.02 % xylan removal, and 86.68 % lignin removal was achieved under mild pretreatment conditions. The 62.18 % of xylose in aqueous phase, and 83.44 % of lignin from organic phase were recovered after the EPH/PTA biphasic pretreatment. Furthermore, the solid residue was digested with high enzymatic glucose yield of 92.69 %, and the xylose was oxidated with xylonic acid yield of 50.06 %. Meanwhile, the high-performance lignin-based films were manufactured by using the recovered lignin. This study presented a promising way for high-value utilization of lignocellulosic biomass.

Effect of temperature on the physicochemical properties and solute–solvent interactions of a dilute solution of [Bmim][OAc] in DMSO

Effect of temperature on the physicochemical properties and solute–solvent interactions of a dilute solution of [Bmim][OAc] in DMSO

Molecular dynamics simulation of CO2 in organic solvent and polymer–solvent solutions

Molecular dynamics simulation of CO2 in organic solvent and polymer–solvent solutions

New imidazole sensors synthesized for copper (II) detection in aqueous solutions

Water security, safety, availability and sustainability of water supply are increasingly problematic and difficult across the planet. Safe and rapid methods have been developed to purify water from cationic pollutants. New imidazole-derived fluorescent sensors, 2-(4,5-diphenyl-1-(p-tolyl)-1H-imidazol-2-yl) phenol (TS) and 2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazol-2-yl) phenol (AS), have been synthesized and characterized, and their possibility as fluorescence sensors for copper (II) has been examined. In CH3CN/H2O (90 v/v), the TS and AS revealed a noticeable an electronic band at 320.00 nm and fluorescence band at 460.90 nm. The ratio metric alterations in the absorption and fluorescence spectra of TS and AS due to the dative covalent bond between them and the copper (II) were shown by the findings of copper (II) titration. The sensing mechanism was validated by optical investigations and FT-IR spectra. In mixed solvent solutions, the selectivity of TS and AS to copper (II) as fluorescent sensors has been demonstrated, with sensitivity as low as 0.09 and 0.28 µM, significantly less than the limit permitted via the US EPA for drinking water (2.00 µM). The identification limits of TS and AS were assessed to be 0.05 and 0.50 µM, respectively, using the spectrophotometric procedure. Stoichiometry binding between TS and AS with copper (II) was found to be 2:1 (tetrahedral structure) as indicated by Job's method.

Quasi-linear homogenization for large-inertia laminar transport across permeable membranes

Porous membranes are thin solid structures that allow the flow to pass through their tiny openings, called pores. Flow inertia may play a significant role in several filtration flows of natural and engineering interest. Here, we develop a predictive macroscopic model to describe solvent and solute flows past thin membranes for non-negligible inertia. We leverage homogenization theory to link the solvent velocity and solute concentration to the jumps of solvent stress and solute flux across the membrane. Within this framework, the membrane acts as a boundary separating two distinct fluid regions. These jump conditions rely on several coefficients, stemming from closure problems at the microscopic pore scale. Two approximations for the advective terms of Navier–Stokes and advection–diffusion equations are introduced to include inertia in the microscopic problem. The approximate inertial terms couple the micro- and macroscopic fields. Here, this coupling is solved numerically using an iterative fixed-point procedure. We compare the resulting models against full-scale simulations, with a good agreement both in terms of averaged values across the membrane and far-field values. Eventually, we develop a strategy based on unsupervised machine learning to improve the computational efficiency of the iterative procedure. The extension of homogenization towards weak-inertia flow configurations as well as the performed data-driven approximation may find application in preliminary analyses as well as optimization procedures towards the design of filtration systems, where inertia effects can be instrumental in broadening the spectrum of permeability and selectivity properties of these filters.

Physicochemical Exploration of Some Biologically Potent Molecules Prevailing in Aqueous Solution of an Anticoagulant Drug with the Manifestation of Solvation Consequences

Aims: Our research aims to uncover how solute-solvent and solute-solute interactions behave in aqueous solutions, exploring how temperature variations and concentration changes influence these interactions. This can provide deeper insights into the behavior of molecules in different environments, potentially leading to applications in fields such as drug delivery, chemical reactions, and material science. Background: In the aqueous ternary system, the physicochemical interactions between a medically powerful pharmacological molecule and two naturally occurring amino acids were explored. The investigations were performed in a dilute to infinite dilute medium to study the interactions between the solutes and solvent extensively. Objective: The objective of this research is to systematically investigate the nature of solute- solvent and solute-solute interactions in aqueous solutions across a range of temperatures and concentrations. By doing so, we aim to elucidate the underlying principles governing these interactions, which could contribute to a deeper understanding of solution chemistry. This knowledge is intended to inform the development of more efficient and effective applications in various scientific and industrial fields, including drug formulation, catalysis, and material design. Method: To characterize and calculate the interactions in the ternary system, various models and formulas were considered and applied. Based on various parameters, including viscosity B-coefficient, apparent molar volume, and molar conductance from viscosity, density, and conductance studies, varying temperatures and concentrations were used to elucidate the molecular interactions. To elucidate the interactions between solute with co-solute and with solvent, the limiting apparent molar volumes and the experimental slopes, derived from the Masson equation, and the Viscosity constants A and B, obtained via the Jones-Doles equation, were examined. To illustrate the structure- breaking/ making character of the solutes in the solution, Hepler’s method and dB/dT values were applied. Results: The results indicated that hydrophobic-hydrophobic interaction plays a significant role in the system. Conclusion: These amino acid interaction models may explain the properties of a variety of physiologically active compounds, and the mechanism can be expanded to comprehend the nature of similar systems. Furthermore, the research could lead to advancements in areas such as pharmaceutical sciences, where controlling solute interactions is crucial for drug delivery systems, and in environmental chemistry, where understanding pollutant behavior in water is essential for remediation efforts.

Pyrrole-hybridized spiro[chromeno[4,3-b]cycloalka[4,5]thieno[3,2-e]pyridine]cycloalkanes as modified tacrine system: Synthesis, structure, and photophysical evaluation

This paper reports the synthesis, structural elucidation, and investigation of the photophysical properties of a novel heterocyclic system, such as pyrrole-hybridized polyhydro-spiro[chromeno[4,3-b]cycloalka[4,5]thieno[3,2-e]pyridine]cycloalkanes (3), where the spirocycloalkanes are cyclopentane, cyclohexane, and cycloheptane; and the cycloalka[4,5]thieno are cyclopenta-, cyclohexa-, and cyclohepta-. These hybrid scaffolds 3 resulted from N-derivatization reactions of a series of twelve examples of modified 7-amino-substituted precursors 1, which, via the Clauson-Kaas reaction using 2,5-dimethoxy-tetrahydrofuran (2,5-DMOTHF) as a CCCC block, were applied to enable the construction and isolation of twelve mentioned pyrrole derivatives 3 in yields of 66 – 95 %. Compounds 3 were structurally fully characterized by melting point, 1H-, 13CNMR, and 1H13C– 2D-NMR (HSQC and HMBC) spectroscopy, X-ray diffraction, and HRMS analysis. The novel pyrroles 3 had their photophysical properties investigated (absorption and emission) in solution in several solvents. As a result, it was found that these pyrroles, where the transition bands were observed in the UV region, exhibit moderate luminescent and shorter lifetime decay values, which are related to and dependent on the spiromoiety and/or cycloalkanes directly fused to the thiophene ring of this new tacrine-modified system.

Performance and Durability of Membrane Electrode Assemblies Using a Non-Precious Metal Catalyst on Both Electrodes and a Hydrocarbon-Based Electrolyte for Anion Exchange Membrane Water Electrolysis

Anion exchange membrane water electrolysis (AEMWEs) can use non-noble metal catalysts because the system is alkaline, and, like proton exchange membrane water electrolysis cells (PEMWEs), it has a membrane-electrode assembly (MEAs) structure. Therefore, it is expected to achieve both lower costs and higher output by using non-precious metals, including peripheral materials such as porous transfer layers (PTLs). Most of the research cases of AEMWEs are focused on the material development and physical property evaluation of electrocatalysts and anion-conductive polymers, and the deterioration mechanism of materials under actual operating AEMWE conditions remains largely unknown. In addition, many high-performance AEMWEs use noble metal catalysts for both the anode and cathode 1. Therefore, in this study, with the aim of converting AEMWEs cells to non-precious metals, we used Ni0.8Co0.2Ox catalyst 2 and Ni0.8Fe0.2Ox catalyst 3, which were independently developed at the University of Yamanashi, as electrocatalysts, and QPAF-4 4, an AEM that was also developed at the University of Yamanashi. We evaluated water electrolysis in a noble metal-free AEMWE cell using anion-conductive polymers for the electrolyte membrane and ionomer, aiming to achieve high electrolytic performance and durability.The catalyst ink for the anodes was prepared by mixing the Ni0.8Co0.2Ox catalyst (University of Yamanashi) with solvent (water/methanol) and QPAF-4 (IEC = 2.0 meq g-1, University of Yamanashi) binder solution. The anode ink was coated by using pulse-swirl-spray (PSS, Nordson) on the QPAF-4 membranes (thickness 50 μm, IEC = 1.5 meq g-1) to make the catalyst-coated membranes (CCMs) with the anode. Catalyst inks for the cathodes were prepared by mixing Ni0.8Fe0.2Ox catalyst (University of Yamanashi) with solvent (water/methanol) and QPAF-4 (IEC = 2.0 meq g-1) binder solution. The cathode ink was coated by using PSS on the gas diffusion layer (GDL, TGP-H-120, Toray) to make the gas diffusion electrodes (GDEs) for the cathodes. Ni mesh (Bekaert.co.jp) was used for the anode GDLs. The single cell (Figure 1, cell structure developed by Yokohama National University) performances were measured while supplying 1 M KOH at 80 °C to both electrodes.The initial performance results showed that the electrolytic performance tended to improve as the cathode I/C increased when both electrodes were supplied with aqueous KOH, as well as when only the anode was supplied with aqueous KOH (Fig. 2-a, b). Since the movement of cathode reactants and produced substances strongly depends on the amount and distribution state of ionomer in the catalyst layer, the increasing I/C levels helped to improve the effectiveness of the water electrolysis reactions, thus contributing to improving the performance. These results indicate the possibility of adopting non-precious metal catalysts for both electrodes in AEMWE, thereby significantly lowering the catalyst cost. Acknowledgement This work was partially based on results obtained from a project, JPNP20003, commissioned by the New Energy and Industrial Technology Development Organization (NEDO) and on GteX Program Japan Grant Number JPMJGX23H2. References 1) A. W. Tricker et al., J. Power Sources, 567, 232967 (2023)2) G. Shi et al., ACS Catal., 12, 14209 (2022).3) G. Shi et al. ACS Omega, 8, 13068-13077 (2023).4) H. Ono et al., J. Mater. Chem. A, 5, 24804 (2017). Figure 1

Understanding PEMFC Catalyst Ink Component Interactions Using Rheo-Impedance Measurement

Optimizing electrode performance remains a grand challenge for fuel cell researchers, particularly in proton exchange membrane fuel cell (PEMFC) catalyst layers (CLs). These layers are typically fabricated from inks containing carbon-supported platinum catalyst particles and ion-conducting polymer material, dispersed in a solvent solution. Variations in catalyst ink formulations result in distinct interactions among ink components, shaping the microstructure and performance of CLs. Additionally, fabrication processes play a crucial role in determining the final properties and microstructure of these CLs. Therefore, understanding the correlation between precursor ink, catalyst morphology, and performance is essential in materials and design optimization for fuel cell technology.This study investigates the interactions within PEMFC catalyst ink using various ink component formulations. We employ a combination of rheological and electrical impedance spectroscopy measurements (rheo-EIS) to probe the static and dynamic nature of catalyst ink. The observed properties, coupled with zeta (ζ) potential and dynamic light scattering (DLS) measurements, provide insights on ink agglomeration levels and microstructure evolution. The experimental approach and findings offer a deeper understanding of ink component-CL structure relationships, guiding the engineering of catalyst inks tailored for practical and optimal performance.

A New Approach to Synthesis of Porous Si Anode for Li-Ion Batteries Via Organic-Solvent Assisted Etching

Silicon (Si) has been regarded as a promising anode for Li-ion batteries due to its high theoretical capacity (4200 mAh/g) compared to graphite anode (372 mAh/g). However, it undergoes significant volume changes (~ 300%) during lithiation and delithiation, leading to particle pulverization and continuous electrolyte decomposition on Si surface, which hinders its practical application. The porous silicon obtained by wet etching method using hydrogen fluoride (HF) can accommodate the volume changes and improve the overall performance of silicon anodes. However, HF etching is highly corrosive, leading to the generation of excess heat and bubbling, lower yields, and difficult to scale-up. Furthermore, the water in etchant oxidizes the newly exposed Si, generating more SiOx, which also cause over-etching of Si and worsen electrochemical performance.Herein, we report an organic-solvent assistant etching process for Si anode. In this process, selected organic solvent were mixed with the HF etchant. When micron sized Si/SiOx powder was added to the solution, the organic solvent in the mixed solution will preferentially be absorbed on the surface of Si/SiOx powder and form a shield which can enable controlled etching of silicon oxide (SiOx) and prevent direct contact between water and newly etched Si surface. This method leads to controllable etching of Si and avoids bubbling/overheating, results in a higher Si yield. The maximum temperature during the etching process is less than ~30°C. The various process parameters, including etchant composition, stirring speed, and time have been optimized to maximize the yield and electrochemical performance of the Si anode. A Si-based anode with organic-solvent assisted etching process has demonstrated improved cycling performance in a Si||Li(Ni0.6Co0.2Mn0.2)O2 (NMC622) full cell. It also leads to low swelling in both particle and electrode levels required for the next generation of high-energy LIBs. Similar organic-solvent assisted etching process can also be used in safe-etching of a broad range of materials.

Impact of Silicon Content on the Behavior of Graphite/Silicon Composite Anodes for High-Performance Lithium-Ion Batteries: Insights from Multi-Scale Simulations

Lithium-ion batteries (LIBs) are critical components in various electronic devices and electric vehicles, driving the need for enhanced performance and efficiency. Graphite has been a popular choice as an anode material due to its stability and conductivity. However, to meet the increasing demand for higher energy densities, silicon has emerged as a promising candidate owing to its high theoretical specific capacity [1]. In this study, we explore the behavior of graphite/silicon (Gr/Si) composite anodes for LIBs.Our investigation focuses on varying the silicon content within the composite anode (ranging from 0% to 20%) to understand its impact on the electrochemical performance. We employ micro-scale simulations by discrete element method (DEM) to provide insights into the evolution of the electrode morphology, including intercalation, particle size distribution, porosity, and tortuosity [1]. Moreover, to analyze the lithiation and delithiation processes, voltage, and energy density considering the morphological of anode, we utilize LIB simulation with Gr/Si, 1.0 M LiPF6 solution in EC-EMC solvent, and lithium metal were used for the anode, electrolyte, and cathode, respectively. The evaluation used three different constant charging rate (C-rate) conditions (0.5 C, 1 C and 2 C).This approach allows us to elucidate the structural evolution and mechanical stability of the composite anode during charge-discharge cycles. Additionally, Gr/Si electrodes display voltage hysteresis, attributed to the influence of the charge-discharge history on the equilibrium potential of the lithium-silicon intercalation reaction [2]. Through simulations, we can explore how the silicon content affects this voltage hysteresis. It becomes more pronounced with a higher content of silicon and at lower states of charge (SOCs). Furthermore, increasing the charging rate will amplify the hysteresis.Our comprehensive analysis aims to provide valuable insights into the intricate interplay between material composition, electrode morphology, and electrochemical performance, facilitating the development of high-performance LIBs with improved energy density and cycling stability. This detailed abstract highlights the computational framework, specific simulation methods, and key variables involved in the investigation of Gr/Si composite anodes, providing a more in-depth overview of the research approach and objectives.Acknowledgement: This research was carried out under the project (Grant Number JPMJMI24G1) supported by the JST-Mirai Program, Japan.

Probing Electrochemical Reactions at the Electrode-Electrolyte Interface in Lithium Metal Battery, Combining Experimental Approach and Computational Calculation

Lithium-ion batteries have attracted significant attention for applications such as energy supply for electric vehicles, large-scale stationary power sources, and energy storage for renewable energy. Research and development of various electrode materials continue for further increasing charge / discharge capacity, expanding operation lifetime. Theoretical capacity of lithium metal is 3860 mAh/g, which is approximately 10 times larger than that of graphite negative electrode (372 mAh/g), which is commonly used in conventional lithium-ion batteries. Therefore, lithium metal batteries, which combine lithium metal negative electrode with a commonly used Lithium nickel manganese cobalt oxides (NCM) positive electrode, are expected to significantly increase energy density and considered to be one of the promising next-generation batteries. Improving the performance of the electrolyte solution is essential to fully utilize the newly developed electrode materials for both positive and negative electrodes. As lithium metal exhibits the most negative potential (-3.04 V v.s. SHE), the electrolyte solution must possess high reduction stability. At the same time, passivation film, solid electrolyte interface (SEI), formed on lithium metal also plays an important role to prevent further decomposition of electrolyte solution. Meanwhile, positive electrodes have oxidation potentials of 4.2 V or higher, and the reactivity at the positive electrode (cathode) and the electrolyte interface (CEI) is also a crucial factor influencing the performance of lithium metal batteries. Thus, controlling the reactions of the electrolyte solution at the electrode interface is a critical factor for operating lithium metal batteries stably and reliably over the long term.In recent years, research and development of electrolyte solutions have focused on enhancing reduction and oxidation stability by exploring various types of solvents, electrolyte salts, and controlling their concentrations. Ether-based electrolyte solutions are known for their higher reduction stability comparing commercially available carbonate-based electrolyte solutions. However, the oxidative stability of conventional concentration ether-based electrolyte solution is quite low, leading the decomposition at oxidation potentials over 4 V. Strategies to improve the oxidative stability of ether-based electrolyte solutions have been extensively studied, and one of the candidates is increasing electrolyte salt concentration.In this study, we have conducted electrochemical performance tests on lithium metal batteries using a concentrated electrolyte solution of ether-based solvents and LiFSI (Lithium bis(trifluoromethanesulfonyl)imide), with lithium metal and NCM positive electrode. As the solvation structures in the electrolyte solution directly affect the formation mechanism of SEI and CEI, the solvation structures are estimated by Raman spectroscopy, and their chemical stability and decomposition mechanisms are estimated by DFT calculations. We have conducted detailed analyses of reduction and oxidative decomposition reactions occurring at the electrode surface, and confirmed the applicability of the prediction combining Raman spectroscopy and DFT calculation. Figure 1

Ion Transport and Solution Behavior of Polyanion-Type Li Salts in Nonaqueous Solvents

To achieve fast charging and discharging of Li-ion batteries, it is important to improve the ionic conductivity (σ) of the electrolyte as well as the Li-ion transference number (t Li) [1]. While nonaqueous polyelectrolyte solutions exhibit high Li-ion transference number(t Li = 0.81) upon immobilization of the anion on a polymer backbone, the ionic conductivity (σ = 1.3 mS cm-1) is inferior to that of conventional electrolytes (σ ~10 mS cm-1). One of the reasons for the low ionic conductivity is low dissociation degree caused by the counter-ion condensation on the polymer backbone. To gain an insight into a design strategy of polyelectrolyte-based liquid electrolytes for LIBs, we studied the effects of polyelectrolyte structure and solvent polarity on the transport properties and Li-ion solvation of the polyelectrolytes in carbonate solvents. Here, we employed two polyelectrolyte copolymers with different sequences; random copolymers of the Li salt of a weakly coordinating polyanion, poly[(4-styrenesulfonyl)-(trifluoromethanesulfonyl)amide] (poly(LiSTFSA)) with neutral comonomer unit, and poly[(4-maleimide-N-[(trifluoromethyl)sulfonyl]-benzenesulfonamide lithium salt] (poly(sa-PMI))-based alternating copolymers with neutral comonomer unit. For the random copolymers, the ionic conductivity increased as the ratio of the neutral comonomer increased. This was attributed to the suppression of counter-ion condensation and increased dissociation. The alternating copolymer solution showed higher dissociation than the random copolymers. The highest ionic conductivity was unexpectedly observed for the lowest polar mixture (such as a dimethyl carbonate rich mixture) at the highest salt concentration despite the low dissociation degree of the polyelectrolytes. A unique conduction resulting from the faster diffusion of transiently solvated Li ions along the interconnected aggregates of polyanion chains was suggested in the highly concentrated polyelectrolyte solutions in low polar solvents. A Li/LiFePO4 cell using the polyelectrolyte solution demonstrated a good charge-discharge performance and rate capability[2].

Oxide Speciation and Oxy-Fluoro Complexes in Molten Fluoride Salts

The presence and speciation of oxides are relevant to various engineering applications of molten fluoride salts. Here, our studies are directed toward two primary applications: 1) as coolants, fuel salts, or breeding blankets in advanced fission and fusion reactors, and 2) as the reaction medium for the novel direct synthesis of Li-ion battery cathodes from Li-ores.In an advanced nuclear reactor, oxide might be introduced to the molten fluoride coolant/blanket via ingress of oxygen or moisture from air. Oxygen and moisture act as oxidants, reacting with the metal fluoride to produce metal oxides or hydroxides, along with corrosive HF. By these reactions, the presence of oxide is an indicator of leaks as well as of the progression of corrosion. Quantification of oxides by square wave voltammetry (SWV) has been proposed as a technique for electrochemical oxide sensors [1]. The intensity of the peak current for the oxidation of oxide to oxygen gas is proportional to the quantity of oxide present, so comparison to a calibration curve can indicate how much oxide is present in the melt. True engineering systems, however, would likely contain multiple solutes including corrosion products, fission products, and activation products. Multi-component chemistries are further complicated by differences in solvent-solute interactions; different fluoride solvents have varying degrees of polymerization, so they incorporate solutes into their structure differently. Practically, this means that oxides may exist in different complexes depending on the solvent and other solutes, therefore oxide quantification via SWV is complicated by solvent and solute chemistry.The synthesis of Li-ion battery cathodes via reaction in molten fluoride salts is currently being studied within a DOE Office of Science BES project as a lower-carbon emissions alternative to traditional cathode manufacturing. This concept involves the dissolution of spodumene (LiAlSi2O6) in molten fluorides and the electrochemical deposition of disordered transition metal (M) oxyfluoride anion rocksalt (Li1+xTM1-xO2-zFz) for use as a battery cathode. The anion disorder in the rocksalt is relevant due to its relation to cathode performance. Energy storage capacity from the transition metal redox states increases as F is substituted for O. Cathode synthesis, therefore, requires tuning of the chemical potentials and transport properties in melts containing fluoride and oxide anions. In this context, a deeper understanding of the structure and speciation of oxide in molten fluorides is critical to formulating the reaction pathway and required composition and configuration of the rocksalt product.Given these applications, we investigate the speciation of oxide and its existence within oxo-fluoro complexes in molten fluoride salts using electrochemistry. We present results of electroanalytical studies of oxides in molten 2LiF-BeF2 and 46.5LiF-11.5NaF-42KF, using cyclic voltammetry and SWV. We make connections between solute speciation and solvent structure, allowing for mutually enhanced understanding of solubility and fluoroacidity. Broadly, electroanalytical studies provide a deeper understanding of oxide’s speciation in molten fluoride systems which, in turn, informs electrochemical sensor development and electrochemical synthesis processes. By investigating the fundamental science of oxide and oxide complexes, we hope to advance technologies which enable the transition to clean energy.[1] L. Massot, L. Cassayre, P. Chamelot, and P. Taxil, “On the use of electrochemical techniques to monitor free oxide content in molten fluoride media,” J. Electroanal. Chem., vol. 606, no. 1, pp. 17–23, Aug. 2007, doi: 10.1016/j.jelechem.2007.04.005.

Observing the Nanoaggregates in the Electrolytes by Small-Angle X-Ray Scattering

The solution solvation structure of the liquid electrolyte directly affects transport properties, which ultimately determines the performance of batteries. It has been predicted that the nanoscale units such as clusters and aggregates in the liquid electrolytes, especially as the salt concentrations increase. However, more is needed to know about these structures due to the limitations of the traditional methods. Currently, there are no direct methods that can be used to investigate the cluster or nanoaggregates in the electrolytes. Herein, we demonstrate that small-angle X-ray scattering-wide angle X-ray scattering (SAXS-WAXS), and even ultra-small-angle X-ray scattering (USAXS) could be applied to capture these larger aggregates in the electrolytes, including conventional organic electrolytes, high concentration electrolytes, water-in-slat electrolytes, and redox-active electrolytes. Raman, neutron scattering, IR, and molecular dynamics (MD) simulations further support the proposed structures. This work highlights the fundamental structure analysis in the nanoscale, which will prompt better electrolytes in the future.

Effect of Deep Eutectic Solvent (DES) on physicochemical and electrochemical properties of triethylmethylammonium tetrafluoroborate in propylene carbonate and aqueous propylene carbonate solvent systems for energy storage applications: A comparative analysis

The use of non-toxic and biodegradable Deep Eutectic Solvents (DES) in energy storage has attracted a lot of attention as the toxic, costly and flammable organic electrolytes do not seem to be sustainable for the environment. So, to analyse the potential of DESs in this area their physicochemical properties and molecular interaction study can be quite helpful. The measurements were made of the density, sound speed, and electrical conductivity of Triethylmethylammonium Tetrafluoroborate (TEMABF4) at four different temperatures in two different solvent systems: propylene carbonate (PC) with ethaline DES (a mixture of ethylene glycol and chlorine in a 1:2 ratio) added as an additive, and binary aqueous PC with ethaline DES again, added as an additive. Density and speed of sound measurements were used to determine the physicochemical characteristics such as apparent molar volume and partial molar volume), apparent molar isentropic compressibility and partial molar isentropic compressibility and limiting molar expansibilities. The effects of DES on the intermolecular interactions in the PC and aqueous PC solvent environment were demonstrated using these parameters. The findings demonstrated that the solute–solvent interactions in both systems were enhanced by the addition of DES. Hepler’s constant additionally showed that TEMABF4 behaved as a structure maker in the DES in aq. PC system and a structure breaker in the DES in PC system. In order to investigate the electrochemical applications, the electrochemical stability and electrical conductivity of the systems being studied are also reported in this paper.

Development of Alginate Hydrogels Incorporating Essential Oils Loaded in Chitosan Nanoparticles for Biomedical Applications.

A hybrid alginate hydrogel-chitosan nanoparticle system suitable for biomedical applications was prepared. Chitosan (CS) was used as a matrix for the encapsulation of lavender (Lavandula angustifolia) essential oil (LEO) and Mentha (Mentha arvensis) essential oil (MEO). An aqueous solution of an acidic Natural Deep Eutectic Solvent (NADES), namely choline chloride/ascorbic acid in a 2:1 molar ratio, was used to achieve the acidic environment for the dissolution of chitosan and also played the role of the ionic gelator for the preparation of the chitosan nanoparticles (CS-NPs). The hydrodynamic diameter of the CS-MEO NPs was 130.7 nm, and the size of the CS-LEO NPs was 143.4 nm (as determined using Nanoparticle Tracking Analysis). The CS-NPs were incorporated into alginate hydrogels crosslinked with CaCl2. The hydrogels showed significant water retention capacity (>80%) even after the swollen sample was kept in the aqueous HCl solution (pH 1.2) for 4 h, indicating a good stability of the network. The hydrogels were tested (a) for their ability to absorb dietary lipids and (b) for their antimicrobial activity against Gram-positive and Gram-negative foodborne pathogens. The antimicrobial activity of the hybrid hydrogels was comparable to that of the widely used food preservative sodium benzoate 5% w/v.

Solubility prediction and interaction mechanism of FOX-7 in ten solvents by molecular and thermodynamic modeling

Solubility is a fundamental physicochemical property of materials. Current solubility prediction models are often highly parameterized by existing data, leading to a serious issue of transferability; thus, it is still challenging to enhancing their accuracy and generalization-ability. In this study, we employ molecular dynamics (MD) simulations and some thermodynamic modeling methods (SMD, COSMO-RS, and COSMO-SAC) to predict the relative solubility of 1,1-diamino-2,2-dinitroethylene (FOX-7) in ten solvents. A meticulous comparison with experimental data reveals that the alchemical free energy approach based on MD simulations outperforms SMD, COSMO-RS and COSMO-SAC models in solubility prediction. Furthermore, we identify that the more negative solvation free energy corresponds to the higher solubility, and the stronger solute–solvent hydrogen bonding corresponds to the higher solubility for low polar solvents too. Finally, it is confirmed that the electrostatic attraction dominates the binding energy between solute and solvent molecules. This work transcends traditional solubility prediction by offering a robust theoretical framework and computational strategy, proving both economical and environmentally benign. It paves the way for the rational selection of solvents for FOX-7 crystallization and provides a versatile tool for predicting the solubility of organic compounds.

Hierarchical Intercalation of Solvated Tetrafluoroborate Anions into Graphite Electrodes: The Case Studies of Methyl Acetate and γ-Butyrolactone Solutions.

Intercalation of anions unlocks graphite as a positive material in energy storage devices, and the performance could be affected by solvents in solutions. In this context, it is vital to investigate the role of solvents in anion intercalation. Herein, a hierarchical intercalation phenomenon, in which different graphite intercalation compounds are generated in the same solution, is studied in lithium tetrafluoroborate (LiBF4) solutions of carboxylate ester solvents γ-butyrolactone (GBL) and methyl acetate (MA). The evolution modes of the graphite cathode structure during electrochemical intercalation and deintercalation are discussed via in situ X-ray diffraction (XRD) measurements. Based on this, the relationship between GICs and potentials, together with concentrations, is compared in detail. Furthermore, various graphite materials with different surface properties are applied to adjust the anions' solvation status inside graphite sheets.

Structure, morphology and crystallization behavior of PVDF/Co nanowire nanocomposites under horizontal and vertical magnetic fields

So far, very limited research has been carried out on the fabrication of polyvinylidene fluoride (PVDF) composited with anisotropic magnetic nanostructures such as nanowires or nanorods, which can potentially provide specific reactions to magnetic fields. Here, single crystal Co nanowires (CNWs) with an average length and diameter of about 220 and 12 nm, respectively, are synthesized using a solvothermal method, followed by adding them to PVDF matrix in order to prepare flexible PVDF/CNW nanocomposites by solvent casting and solution crystallization processes at room temperature. The nucleation and growth of PCNW nanocomposites are investigated in the absence and presence of horizontal and vertical magnetic fields. According to FESEM images, in addition to the direction of the applied magnetic field, the presence or absence of CNWs induces different effects on the size of spherulites and the configuration of polymer chains. By adding CNW to the PVDF matrix in the absence of a magnetic field and under a horizontal magnetic field, the size of the spherulites in the pure PVDF film increases about 67 % (from 3 to 5 μm) and 300 % (from 3 to 12 μm), respectively. Under a vertical magnetic field, the addition of CNW reduces the size of the spherulites to 1 μm, thereby forming a film with a combination of spherulites and filamentary structure likely due to the nanowire-nanowire, nanowire-chain and chain-chain interactions. Also non-contact flexible triboelectric nanogenerators of magnetic force are fabricated.