Modulating the Electrolyte Inner Solvation Structure via Low Polarity Co-solvent for Low-Temperature Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries are regarded as the promising candidates for large-scale energy storage systems owing to low cost and high safety;however,their applications are restricted by their poor low-temperature performance.Herein,a low-temperature electrolyte for low-temperature aqueous zinc-ion batteries is designed by introducing low-polarity diglyme into an aqueous solution of Zn(ClO_(4))_(2).The diglyme disrupts the hydrogenbonding network of water and lowers the freezing point of the electrolyte to-105℃.The designed electrolyte achieves ionic conductivity up to16.18 mS cm^(-1)at-45℃.The diglyme and ClO_(4)^(-)reconfigure the solvated structure of Zn^(2+),which is more favorable for the desolvation of Zn^(2+)at low temperatures.In addition,the diglyme effectively suppresses the dendrites,hydrogen evolution reaction,and by-products of the zinc anode,improving the cycle stability of the battery.At-20℃,a Zn‖Zn symmetrical cell is cycled for 5200 h at 1 mA cm^(-2)and 1 mA h cm^(-2),and a Zn‖polyaniline battery achieves an ultra-long cycle life of 10000 times.This study sheds light on the future design of electrolytes with high ionic conductivity and easy desolvation at low temperatures for rechargeable batteries.

Dispersion of ZnO Nanocrytals in Co-solvent and Its Application in Photovoltaic Material

To overcome the aggregation of nanocrystals in a blend of inorganic material with conjugated polymers to prepare photovoltaic material, we used a co-solvent blend of CHCl3 with MeOH at a certain volume fraction to disperse inorganic nanocrystals. The results show that when the volume fraction of MeOH is 50%, ZnO nanocrystals with an average diameter of 30 nm disperse well in the co-solvent solution. Its application in photovoltaic material was investigated in this work, and the photoluminescence（PL） spectra show that when ZnO was 50%（volume fraction） in solution and 25%（volume fraction） in film, the fluorescence quenching reached the maximum values 83.34% and 64.4%, respectively, indicating that electron could transfer from conjugated polymer to electron-acceptor ZnO effectively.

Effect of Co-solvent and Pressure on the Thermal Decomposition of 2,2′Azobis-(isobutyronitrile) in Supercritical CO_2

The thermal decomposition of 2, 2'-azobis (isobutyronitrile) (AIBN) in supercritical CO2 with cosolvent methanol or cyclohexane has been studied by using UV/Vis spectroscopic method at 335.15 K and at 12.0 MPa and 14.0 MPa. Both of the cosolvents can accelerate the decomposition rate, and the effect of methanol is more significant than that of the cyclohexane.

Influence of Co-Solvent on the Extraction Behaviour of Uranium and Thorium Nitrates with Organophosphorous Compounds

Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.

Supercritical Synthesis of Ethyl Esters via Transesterification from Waste Cooking Oil Using a Co-Solvent

Biofuels became more promising alternative to the fossil fuels because of the depletion of fossil resources, renewability, environmental benefits, and energy security. Ethanolysis of waste cooking oil with hexane as co-solvent was carried out for the production of fatty acid ethyl ester (FAEE). This process reduced the severity of process parameters with high purity biodiesel yield. Process variables such as co-solvent ratio, ethanol to oil molar ratio, reaction temperature and reaction time were optimized. The maximum biodiesel yield of 88% was obtained at ethanol/oil molar ratio of 40:1, co-solvent (hexane) to oil ratio of 0.2% (v/v), reaction temperature of 300°C in 20 min of reaction time. Fatty acid ethyl ester (biodiesel) samples produced from this process were measured and evaluated using GC-MS analytical instrument. Thermo gravimetric analysis (TGA) was also performed to examine the thermal stability of waste cooking oil, ethyl esters and fuel blends. Fuel properties of ethyl esters were determined and compared with the ASTM standards for biodiesel, regular diesel and ethyl esters from different feedstock.

Enhancement of Lipase-catalyzed Synthesis of Caffeic Acid Phenethyl Ester in Ionic Liquid with DMSO Co-solvent

Caffeic acid phenethyl ester(CAPE) is a natural and rare ingredient with several biological activities, but its industrial production using lipase-catalyzed esterification of caffeic acid(CA) and 2-phenylethanol(PE) in ionic liquids(ILs) is hindered by low substrate concentrations and long reaction time. To set up a high-efficiency bioprocess for production of CAPE, a novel dimethyl sulfoxide(DMSO)–IL co-solvent system was established in this study.The 2%(by volume) DMSO–[Bmim][Tf2N] system was found to be the best medium with higher substrate solubility and conversion of CA. Under the optimum conditions, the substrate concentration of CA was raised 8-fold,the reaction time was reduced by half, and the conversion reached 96.23%. The kinetics follows a ping-pong bi-bi mechanism with inhibition by PE, with kinetic parameters as follows: Vmax= 0.89 mmol · min-1· g-1, Km,CA=42.9 mmol · L-1, Km,PE= 165.7 mmol · L-1, and Ki,PE= 146.2 mmol · L-1. The results suggest that the DMSO cosolvent effect has great potential to enhance the enzymatic synthesis efficiency of CAPE in ILs.

Effects of Water-Soluble Co-Solvent on Properties of W/O Pickering Emulsions

Effects of water-soluble co-solvents （WSCs）on the properties of water/oil Picketing emulsions were investigated. Picketing emulsions were prepared in the system of 1,2,4-trimethylbenzene （TMB）/hydrophobic sil- ica/water with varied concentrations of WSCs （ethanol, acetic acid and glycerin）. Mean droplet diameter distribu- tions of the obtained emulsions were studied to investigate the effects of WSCs types and concentrations. The results demonstrated that mean droplet diameter distributions decreased at first and then increased with the increase of WSC concentration. Moreover, the effect of WSC concentration on the phase inversion locus was further investi- gated. At the same time, infrared radiation （IR）spectrometer was used to investigate the mechanism. The results showed that the WSC attaching on hydrophobic silica changed the wettability of the particles, which facilitated the formation and phase inversion of the emulsion. The hydrogen bonds between the co-solvent groups attaching on the solid particles made a great effect on the droplet size of the emulsion and strengthened the interaction among emulsifiers. Overall, proper WSC was in favor of the stability of Picketing emulsion.

Optimization of Biodiesel Production from Waste Vegetable Oil Assisted by Co-Solvent and Microwave Using a Two-Step Process

The two-step catalyzing process for biodiesel production from waste vegetable oil was assisted by both co-solvent and microwave irradiation. Central composite design (CCD) was employed to optimize the reaction conditions. Optimal reaction conditions of the first step were alcohol to oil molar ratio of 9:1, catalyst (H2SO4) amount 1 wt%, reaction temperature 333 K, and reaction time 7.5 minutes;while for the second step, optimal reaction conditions were alcohol to oil molar ratio 12:1, catalyst (NaOH) amount 1 wt%, reaction temperature 333 K, and reaction time 2.0 minutes. The total reaction time was 9.5 min and the conversion rate of fatty acid methyl esters (FAMEs) achieved was 97.4%. The total reaction time was shorter than previous studies. Therefore, the co-solvent and microwave assisted two-step catalyzing process has a potential application in producing biodiesel from waste vegetable oil.

An effective'salt in dimethyl sulfoxide/water'electrolyte enables high-voltage supercapacitor operated at-50℃

Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.

Oxidation of n-Butanol and 2-Pentanol with Molecular Oxygen in Supercritical CO2

Oxidation of n-butanol and 2-pentanol using molecular oxygen in supercritical (SC) CO2 with and without co-solvent is investigated. The results showed that the reaction selectivity is high when the reaction is carried out in SC CO2. It has been observed that co-solvent affects conversion and selectivity of the reaction considerably.

Fabricating low-temperature-tolerant and durable Zn-ion capacitors via modulation of co-solvent molecular interaction and cation solvation

Aqueous Zn-based energy-storage devices have aroused much interest in recent years.However,uncontrollable dendrite growth in the Zn anode significantly limits their cycle life.Moreover,the poor low-temperature performance arising from the freezing of aqueous electrolytes at sub-zero temperatures restricts their practical applications in cold regions.Here,we fabricated low-temperature-tolerant and durable Zn-ion hybrid supercapacitors(ZHSCs)via modulating a co-solvent water/ethylene glycol electrolyte.The interaction of intermolecular hydrogen bonds between water and ethylene glycol as well as cation solvation was systematically investigated by tuning the co-solvent composition.The results illustrate that the ZnSO_(4)/water/ethylene glycol(65%)electrolyte possesses high ionic conductivity at low temperatures and effectively prevents the dendrite formation of the Zn anode.The as-fabricated ZHSCs exhibit long-term cyclability and are capable of working at sub-zero temperatures as low as -40℃.The present ZHSCs are anti-freezing and cost-effective,which may find new applications in the fields of next-generation electrochemical energy storage devices.

Influence of co-solvent hydroxyl group number on properties of water-based conductive carbon pastes

A series of water-based conductive carbon pastes were prepared by wet ball milling, followed by vacuum defoaming using isopropyl alcohol, propylene glycol or glycerin as co-solvents. Screen printing was then used to prepare conductive patterns. To determine the influence of co-solvent hydroxyl group number on the properties of water-based conductive carbon pastes, the rheological properties of the pastes and the surface morphologies and conductivities of the printed patterns were characterized. The results show that paste viscosity increased with the number of hydroxyl groups and the latter also affected thixotropy. In addition, the boiling points and surface tensions of the co-solvents increased consistently with hydroxyl group number, affecting the hydrodynamic flow. The conductive carbon paste created using propylene glycol as a co-solvent was the best for screen printing because of its weak coffee-ring effect and appro- priate rheological properties, resulting in a smooth coating surface and uniform deposition of the fillers. The resistivity of the pattern printed using paste PG, containing the closest packing of conductive carbon black particles, was 0.44 Ω cm.

Solvation dynamics of furazolidone in pure organic solvents and aqueous EDTA disodium salt mixtures:molecular interactions and thermodynamic insights

This study systematically examined the dissolution behavior of furazolidone in 12 different pure solvents and in aqueous solutions containing ethylenediaminetetraacetic acid disodium salt(EDTA-2Na).The solubility data indicated that polar aprotic solvents demonstrated a marginally higher solubility of furazolidone compared to alcohols and water.Interestingly,a co-solvency effect was observed in the aqueous solutions of EDTA-2Na,where the solubility of furazolidone initially increased and then decreased with the gradual addition of EDTA-2Na,peaking at a mass fraction of 0.03(1.949×10^(–5)at 323.15 K).The analysis using the Kamlet-Abboud-Taft Linear Solvation Energy Relationship(KAT-LSER)model suggested that the dissolution of furazolidone in these systems was predominantly influenced by non-specific solute-solvent and solvent-solvent interactions.Furthermore,Hansen solubility parameter calculations revealed that N,N-dimethylformamide(DMF)and N,N-dimethylacetamide(DMAC)exhibited superior dissolution capabilities compared to other solvents.It was also found that the partial solubility parameters played a crucial role in determining the overall solubility behavior.