Alcohol Cosolvents Research Articles

Cosolvents effect on supercritical CO2 microemulsion containing ionic Liquid: Experiment and simulation

Supercritical carbon dioxide (scCO2) microemulsion containing ionic liquids (ILs) 1-ethyl-3-methylimidazolium acetate ([Emim]Ac) were prepared under mild operating conditions with the help of surfactant branched secondary alcohol ethoxylates (TMN-6) and cosolvents (water and ethanol). Phase equilibrium experiments and molecular dynamics (MD) simulations were conducted from gas-phase system, two-phase system to supercritical system. The conditions of constructing supercritical microemulsion were studied by using self-made phase equilibrium device. The effects of temperature, surfactant concentration, and cosolvent concentration on cloud point pressure (CPP) were studied. The results showed that the transparent and uniform microemulsion could not be formed in gas-phase and two-phase systems. In supercritical system, the proper addition of cosolvent water and ethanol contributed to the formation of microemulsion and the dissolution of ILs. However, the reduction effect of CPP was not obvious or even increased when only water was added. After added water and ethanol simultaneously, not only did the maximum WIL increase to 0.26, but CPP also significantly decreased. MD simulation was conducted to characterize the microstructure of three systems. Furthermore, the gyration radius, radial distribution function (RDF), and hydrogen bond dynamics were calculated to analyze the strengthening mechanism of cosolvents on self-assembly. The simulation results revealed that, water promoted the interaction between hydrophilic groups of surfactants and ionic liquids, while ethanol constructed a hydrogen bonding network between continuous and dispersed phases. Water and ethanol have synergistic effect on the preparation of supercritical microemulsion, which has a good effect on improving the self-assembly rate and aggregate stability.

Solution Processing of Spinel Nickel Cobaltite: Exfoliation Mechanism, Dispersion Stability, and Applications.

The exfoliation of nonlayered materials to mono- or few-layers is of growing interest to realize their full potential for various applications. Nickel cobaltite (NiCo2O4), which has a spinel crystal structure, is one such nonlayered material with unique properties and has been utilized in a wide range of applications. Herein, NiCo2O4 is synthesized from NiCo2- Layered double hydroxides using a topochemical conversion technique. Subsequently, bulk NiCo2O4 is exfoliated into mono- or few-layer nickel cobaltene nanosheets using liquid-phase exfoliation in various low-boiling point solvents. An analytical centrifuge technique is also utilized to understand the solute-solvent interactions by determining their dispersion stability using parameters such as the instability index and sedimentation velocity. Among the studied solvents, water/isopropyl alcohol cosolvent is found to have better dispersion stability. In addition, density functional theory calculations are carried out to understand the exfoliation mechanism. It is found that the surface termination arising from the Co-O bond needs the least energy for exfoliation. Furthermore, the obtained nickel cobaltene nanosheets are utilized as an active material for supercapacitors without any conductive additives or binders. A solid-state symmetric supercapacitor delivers a specific capacitance of 10.2 mF cm-2 with robust stability, retaining ∼98% capacitance after 4000 cycles.

Comparison of Binary Alcohol/Water Solvent Systems to Blood for Extractions of Blood-Contacting Medical Devices.

The analysis of extractables and leachables and subsequent risk assessment is an important aspect of the determination of biocompatibility for many medical devices. Leachable chemicals have the potential to pose a toxicological risk to patients, and therefore it is required that they be adequately characterized and assessed for potential safety concerns. One important consideration in the assessment of leachables is the choice of a suitable simulating solvent intended to replicate the use condition for the device and its biological environment. This aspect of study design is especially difficult for blood-contacting medical devices due to the complexity of simulating the biological matrix. This publication reports a comparison of the extracting power of different binary solvent mixtures and saline in comparison with whole blood for a bloodline tubing set connected to a hemodialyzer. Ten different known extractables, spanning a range of physicochemical properties and molecular weights, were quantified. The results indicated that for low-molecular-weight analytes, a suitable exaggeration for whole blood can be obtained using a low-concentration ethanol/water mixture (≈20%), and in general, extracted quantity increases with the concentration of alcohol cosolvent. For polyvinylpyrrolidone, the opposite trend was observed, as solubility of the polymer was found to decrease with increasing alcohol concentration, resulting in lower extracted quantities at high alcohol concentrations. Analysis of ethanol/water concentrations in the extract solutions post extraction indicated no change in solvent composition.

Understanding the cation exchange affinity in modified-MMT catalysts for the conversion of glucose to lactic acid.

This study investigated the exchange affinity of Fe3+, Cu2+, and Zn2+ cations in sulfuric acid-purified montmorillonite (S-MMT) to enhance Lewis acid sites and subsequently improve the catalytic conversion of glucose to lactic acid. XRD analysis suggested the successful cation exchange process, leading to structural expansion of the resultant cation exchanged-MMTs (CE-MMTs). XRF and TGA indicated that Zn2+ had the highest exchange affinity, followed by Cu2+ and then Fe3+. This finding was further supported by the results of TPD-NH3 analysis and pyridine-adsorption test, which demonstrated that Zn-MMT had the highest total acid sites (TAS) and the ratio of Lewis acid-to-Brønsted acid surface site (LA/BA). These results indicated dominant presence of Lewis acid sites in Zn-MMT due to the higher amount of exchanged Zn2+ cations. Consistently, time-dependent catalytic studies conducted at 170 °C showed that a 7 h-reaction generated the highest lactic acid yield, with the catalytic performance increasing in the order of Fe-MMT < Cu-MMT < Zn-MMT. The study also observed the impact of adding alcohols as co-solvents with water at various ratios on the conversion of glucose to lactic acid catalysed by Zn-MMT. The addition of ethanol enhanced lactic acid yield, while methanol and propanol inhibited lactic acid formation. Notably, a water-to-ethanol ratio of 30 : 70 v/v% emerged as the optimal solvent condition, resulting in ca. 35 wt% higher lactic acid yield compared to using water alone. Overall, this study provides valuable insights into the cation exchange affinity of different cations in MMT catalysts and their relevance to the conversion of glucose to lactic acid. Furthermore, the incorporation of alcohol co-solvent presents a promising way of enhancing the catalytic activity of CE-MMTs.

A New Molecular Insight in Effects of Alcohol Co-Solvents on Miscibility of Anhydrous Ethanol/Diesel Blends

Abstract Sustainable policy leads to partially replace fossil diesel by bio-fuels and ethanol/diesel blends. The major challenge is how to enhance miscibility of ethanol with diesel. Molecular dynamics simulation was applied to study the effects of alcohol co-solvents on miscibility of ethanol with diesel. The 1-heptanol, 1-decanol, n-butanol, and butanol isomers were selected as co-solvents. The diesel model was constructed to quantitatively characterize miscibility and obtain interaction of ethanol and diesel. The solubility parameters, structural feature, and energy properties were analyzed. The results showed that long-chain alcohol co-solvents contributed to miscibility of blends. The aromatics had more effects on miscibility than linear alkanes and cycloalkanes. Radial distribution function results showed that straight-chain alcohols or high linearity co-solvents promoted miscibility of ethanol than branched alcohols. The energy analysis revealed that the hydrogen bonding and van der Waals interaction were the main driving forces to improve miscibility, while polarization interaction had no major contribution. The hydrogen bonding dominated for short-chain alcohols, while van der Waals interaction was vital for long-chain alcohols. The coordination of hydrogen bonding and van der Waals energy in dynamic equilibrium led to the optimal miscibility.

Effects of several cosolvents and non-solvents on ester true solvents in nitrocellulose lacquer thinner

Choosing better organic solvents and providing appropriate mixing ratios for nitrocellulose (NC) lacquer thinner is a very important topic in NC lacquer thinner industries. This paper studied the effects of cosolvents and non-solvents on ester true solvents in NC lacquer thinner. The research objects were ester true solvents (Methyl Acetate (MA) and Ethyl Acetate (EA)), alcohol cosolvents (Ethyl Alcohol (ETA), Isopropyl Alcohol (IPA), and Isobutyl Alcohol (IBA)) and non-solvents (n-Hexane (NX), n-Heptane (NP), and Petroleum Ether (PE)). Nitrocellulose lacquer dissolution experiments, explosion characteristic experiments, and algal growth inhibition experiments were performed. The results indicated that: the mixed organic solvents containing cosolvent of ETA were better than those containing the other two cosolvents (IPA and IBA) in terms of dissolution rates, explosion characteristics, and environmental influences. For non-solvent, NX was a better non-solvent as the dissolution rates of mixed organic solvents (containing MA, ETA, and NX) all kept at relatively higher levels at different non-solvent proportions. NX and PE were safer non-solvents when the concentration of non-solvent was relatively lower (16.7 %). The IC50 values of mixed organic solvents containing non-solvent NT on Dunaliella bardawil were a little bit higher than those of mixed organic solvents containing NX or PE when the volume ratios of non-solvent were the same. In conclusion, the mixed organic solvent of MA (ester true solvent), ETA (alcohol cosolvent), and NX (non-solvent) with a volume ratio of about 4:1:1 was a relatively ideal composition for the industrial application of NC lacquer thinner.

Co-Solvent Assisted Hydrothermal Liquefaction of Algal Biomass and Biocrude Upgrading

This study reports the hydrothermal liquefaction (HTL) of microalgae Spirulina platenesis in the presence of alcohol or formic acid co-solvents. HTL runs are performed in a 1.8-L batch reactor at 300 °C using an alcohol (methanol and ethanol) or formic acid co-solvent. Consequently, hydrodeoxygenation (HDO) of resultant algal biocrude is performed at 350 °C for 2 h under high hydrogen pressure (~725 psi) using the Ru/C catalyst. The HTL results are compared with the control HTL run performed in water only. The results of the study show that the addition of co-solvents leads to a 30–63% increased biocrude yield over the control HTL run. Formic acid results in a 59.0% yield of biocrude, the highest amongst all co-solvents tested. Resultant biocrudes from formic acid-assisted and ethanol-assisted HTL runs have 21.6% and 3.8–11.0% higher energy content, respectively, than that of the control run. However, that of the methanol-assisted HTL results in biocrude with 4.2–9.0% lower energy density. Viscosity of biocrude from methanol- or ethanol-assisted HTL is higher than the control HTL but formic acid-assisted HTL results in a less viscous biocrude product. In addition, the HDO study leads to a 40.6% yield of upgraded oil, which is characterized by a higher net energy content and lower O/C and N/C ratios when compared to the initial HTL biocrude.

Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein.

The self-assembly of the tobacco mosaic virus coat protein is significantly altered in alcohol–water mixtures. Alcohol cosolvents stabilize the disk aggregate and prevent the formation of helical rods at low pH. A high alcohol content favours stacked disk assemblies and large rafts, while a low alcohol concentration favours individual disks and short stacks. These effects appear to be caused by the hydrophobicity of the alcohol additive, with isopropyl alcohol having the strongest effect and methanol the weakest. We discuss several effects that may contribute to preventing the protein–protein interactions between disks that are necessary to form helical rods.

Manipulating Crystallization Kinetics in High-Performance Blade-Coated Perovskite Solar Cells via Cosolvent-Assisted Phase Transition.

Manipulating the perovskite solidification process, including nucleation and crystal growth, plays a critical role in controlling film morphology and thus affects the resultant device performance. In this work, a facile and effective ethyl alcohol (EtOH) cosolvent strategy is demonstrated with the incorporation of EtOH into perovskite ink for high-performance room-temperature blade-coated perovskite solar cells (PSCs) and modules. Systematic real-time perovskite crystallization studies uncover the delicate perovskite structural evolutions and phase-transition pathway. Time-resolved X-ray diffraction and density functional theory calculations both demonstrate that EtOH in the mixed-solvent system significantly promotes the formation of an FA-based precursor solvate (FA2 PbBr4 ·DMSO) during the trace-solvent-assisted transition process, which finely regulates the balance between nucleation and crystal growth to guarantee high-quality perovskite films. This strategy efficiently suppresses nonradiative recombination and improves efficiencies in both 1.54 (23.19%) and 1.60eV (22.51%) perovskite systems, which represents one of the highest records for blade-coated PSCs in both small-area devices and minimodules. An excellent VOC deficit as low as 335mV in the 1.54eV perovskite system, coincident with the measured nonradiative recombination loss of only 77mV, is achieved. More importantly, significantly enhanced device stability is another signature of this approach.

A Novel RP-HPLC Method for Estimating Fulvestrant, Benzoyl Alcohol, and Benzyl Benzoate in Injection Formulation

For the quantitative determination of Fulvestrant, Benzyl alcohol, and Benzyl benzoate in Fulvestrant injection, an original RP-HPLC approach was developed. The gradient method was developed using HPLC and a Phenomenex Luna C8, 150 × 4.6 mm, i.d 3.0 μm particle size column with a gradient programme of mobile phases A and B. With a flow rate of 1.5 mL/minute, injection volume of 10 μL, and column temperature of 35°C, UV wavelength detection at 254 nm for Benzyl alcohol and Benzoyl Benzoate and 280 nm for Fulvestrant, mobile phase-A consists of DI water and mobile phase-B consists of Acetonitrile. The current study describes a single HPLC method for developing a Fulvestrant (Active), Benzyl alcohol (Cosolvent), and Benzyl Benzoate (Cosolvent) assay for Fulvestrant injection. The assay method was determined to be suitable for quantifying three components in the pharmaceutical product and was verified according to ICH guidelines.

Catalytic Liquefaction of Kraft Lignin with Solvothermal Approach

Lignin is a natural biopolymer present in lignocellulosic biomass. During paper pulp production with the Kraft process, it is solubilized and degraded in Kraft lignin and then burned to recover energy. In this paper, the solvolysis of Kraft lignin was studied in water and in water/alcohol mixtures to produce oligomers and monomers of interest, at mild temperatures (200–275 °C) under inert atmosphere. It was found that the presence of alcohol and the type of alcohol (methanol, ethanol, isopropanol) greatly influenced the amount of oligomers and monomers formed from lignin, reaching a maximum of 48 mg·glignin−1 of monomers with isopropanol as a co-solvent. The impact of the addition of various solid catalysts composed of a metal phase (Pd, Pt or Ru) supported on an oxide (Al2O3, TiO2, ZrO2) was investigated. In water, the yield in monomers was enhanced by the presence of a catalyst and particularly by Pd/ZrO2. However, with an alcoholic co-solvent, the catalyst only enhanced the formation of oligomers. Detailed characterizations of the products with FTIR, 31P-NMR, 1H-NMR and HSQC NMR were performed to elucidate the chemical transformations occurring during solvolysis. The nature of the active catalytic specie was also investigated by testing homogeneous palladium catalysts.

Enantioselective Separation of Antiretroviral Drug Combinations on Immobilized Polysaccharide CSPs Under Subcritical Conditions Using Supercritical Fluid Chromatography Apparatus

A stereoselective method has been developed for the chiral separation of the enantiomers of eight antiretroviral (ARV) drugs under subcritical conditions using a supercritical fluid chromatography apparatus. The ARVs: abacavir, tenofovir alafenamide, lamivudine, efavirenz, atazanavir, emtricitabine, dolutegravir and darunavir, are used to treat the human immunodeficiency virus (HIV). The antiretroviral therapy has been planned to manage and control the severity of HIV and prolong the patient’s life. The use of multiple drugs that act on different viral targets is known as highly active antiretroviral therapy, which slows down the development of AIDS and prevents opportunistic infections that often lead to death. The immobilized meta-substituted polysaccharide-derived carbamate columns (CSPs) have been chosen for chiral SFC separation of selected ARVs. The ARVs enantioseparation was achieved on CSPs by using different alcohol co-solvents (methanol, ethanol and isopropyl alcohol) with diethylamine (DEA) as an additive to the mobile phase. These CSPs exhibit an exceptional level of complementary chiral recognition characteristics by applying different screening and method optimization strategies. The cellulose tris(3,5-dichlorophenylcarbamate) immobilized on silica gel was found to be useful for the chiral SFC analysis of abacavir, lamivudine, efavirenz combination ARV analysis, and the method was optimized by studying the effects of different mobile phase additives, column temperatures and flow rates. The amylose tris(3-chloro, 5-methylphenyl carbamate) immobilized on silica gel was found to be useful for the chiral SFC analysis of emtricitabine, abacavir and dolutegravir combination ARV drugs.

Development of a SGJ-1 of Water-Based Anti-Wax Agent

The phenomenon of petroleum wax deposition is very common during oil well production. When the wax molecule condenses on the surface of the pipeline, it will hinder the exploitation of crude oil, reduce the recovery rate of crude oil, and may lead to the blockage of the pipeline when it is serious, so that the oil recovery work will stop. This phenomenon can be obviously changed by using wax cleaning agent. However, the low ignition point and toxicity of oil-based wax remover are not conducive to oil recovery. Therefore, a new water-based paraffin remover SGJ-1 was developed in this paper. The best formula is: wax dispersant 15%, wetting reversion agent 1%, sodium silicate 1%, alcohol cosolvent 8% and 75% water. Condensation point, wax dissolution rate and anti-wax performance of SGJ-1 water-based dewaxing and anti-waxing agent were tested by self-assembly testing device. The experimental results show that the condensation point of SGJ-1 is -34°C, the viscosity reduction effect is good under 35°C, and the wax dissolution rate is 0.0512 g/min, The highest wax prevention rate can reach 89.58% and the wax removal and wax prevention ability is excellent. Compared with other paraffin removers, SGJ-1 can also reduce the viscosity of crude oil, so it has a good development prospect.

Effective utilization of basic nature of WEB in copper catalyzed Chan-Lam N-arylation reaction under ligand free conditions

A mild and green protocol has been developed for a copper catalyzed N-arylation of anilines and imidazoles under external base/additive, promoter and ligand free conditions. The main advantage of this work is that agro waste WEB (Water Extract of Banana Peel Ash) has emerged as solvent as well as base. The reaction protocol avoids hazardous solvents, toxic chemicals, ligands etc. Interestingly addition of alcoholic co-solvent enhanced the yield of the product.

Biodiesel by Co-processing animal fat/vegetable oil mixtures over basic heterogeneous Ca catalyst

The use of vegetable oils to produce biodiesel raises several sustainability issues, namely the fuel/food conflict. The high cost of vegetable oils and an expensive homogeneous base catalyzed process encourages the search for alternative raw materials and more efficient production processes. Biodiesel from beef tallow, a non-edible fat, was produced by methanolysis over calcium based heterogeneous catalyst. The catalyst was prepared by calcination of scallop shells at 800 ​°C. To overcome the undesired effect of the tallow acidity (3.9 mg KOH /g fat ), mixtures of tallow and soybean oil (SBO) (0.6 mg KOH /g fat ) were processed and alcohol co-solvents (isopropanol, 1-propanol, and isobutanol) and biodiesel itself, as a solvent, were used to improve the miscibility of the reaction mixture. Processing of neat tallow promotes an important decay of the catalytic activity due to the partial neutralization of the basic catalyst. Co-processing mixtures of tallow/SBO allowed minimizing the acidity effect. Alcohol co-solvents harmed the biodiesel yield due to competitive adsorption of alcohols with methanol on catalyst active sites but protected the catalyst against adsorption of the reaction mixture species. Biodiesel used as a solvent had an almost null effect on the esterification reaction yield, thus showing the absence of mass transfer limitation. Co-processing low-grade fat with vegetable oil seems to be a feasible strategy to process low-grade fats using basic heterogeneous catalysts, thus contributing to improving the sustainability of biodiesel production. • Low-grade animal fat biodiesel was produced by methanolysis over basic catalyst. • Beef tallow was transesterified over Ca heterogeneous catalyst. • Co-processing tallow and soybean oil minimized fat acidity drawback. • Alcohols and FAME solvents were used to improve reaction mixture miscibility. • Solvents prevent catalyst deactivation by avoiding reaction species adsorption.

The direct synthesis of hydrogen peroxide from H2 and O2 using Pd-Ni/TiO2 catalysts.

The direct synthesis of hydrogen peroxide (H2O2) from molecular H2 and O2 offers an attractive, decentralized alternative to production compared to the current means of production, the anthraquinone process. Herein we evaluate the performance of a 0.5%Pd-4.5%Ni/TiO2 catalyst in batch and flow reactor systems using water as a solvent at ambient temperature. These reaction conditions are considered challenging for the synthesis of high H2O2 concentrations, with the use of sub-ambient temperatures and alcohol co-solvents typical. Catalytic activity was observed to be stable to prolonged use in multiple batch experiments or in a flow system, with selectivities towards H2O2 of 97% and 85%, respectively. This study was carried out in the absence of halide or acid additives that are typically used to inhibit sequential H2O2 degradation reactions showing that this Pd-Ni catalyst has the potential to produce H2O2 selectively. This article is part of a discussion meeting issue 'Science to enable the circular economy'.

Use of Co-Solvents in Hydrothermal Liquefaction (HTL) of Microalgae

This study reviewed and summarized the literature regarding the use of alcohols during hydrothermal liquefaction (HTL) of algal biomass feedstocks. The use of both pure alcohols and alcohol-water co-solvents were considered. Based upon this review, laboratory experiments were conducted to investigate the impacts of different alcohol co-solvents (ethanol, isopropanol, ethylene glycol, and glycerol) on the HTL treatment of a specific saltwater microalga (Tetraselmis sp.) at two temperatures: 300 °C and 350 °C. Based on their performance, two co-solvents, isopropanol and ethylene glycol, were selected to explore the effects of varying solvent concentrations and reaction temperatures on product yields and biocrude properties. The type and amount of added alcohol did not significantly affect the biocrude yield or composition. Biocrude yields were in the range of 30–35%, while a nearly constant yield of 21% insoluble products was observed, largely resulting from ash constituents within the algal feedstock. The benefits of using alcohol co-solvents (especially isopropanol) were the reduced viscosity of the biocrude products and reduced rates of viscosity increase with biocrude aging. These effects were attributed mainly to the physical properties of the co-solvent mixtures (solubility, polarity, density, etc.) rather than chemical processes. Under the reaction conditions used, there was no evidence that the co-solvents participated in biocrude production by means of hydrogen donation or other chemical processes. Recovery and recycling of the co-solvent present various challenges, depending upon the type and amount of the co-solvent that is used. For example, glycol solvents are recovered nearly completely within the aqueous product stream, whereas simple alcohols are partitioned between the biocrude and aqueous product streams. In commercial applications, the slight benefits provided by the use of co-solvents must be balanced by the challenges of co-solvent recovery and recycling.

Efficient Mild Organosolv Lignin Extraction in a Flow-Through Setup Yielding Lignin with High β-O-4 Content.

Current lignin fractionation methods use harsh conditions that alter the native lignin structure, resulting in a recalcitrant material which is undesired for downstream processing. Milder fractionation processes allow for the isolation of lignins that are high in β-aryl ether (β-O-4) content, however, at reduced extraction efficiency. The development of improved lignin extraction methods using mild conditions is therefore desired. For this reason, a flow-through setup for mild ethanosolv extraction (120 °C) was developed. The influence of acid concentration, ethanol/water ratio, and the use of other linear alcohol co-solvents on the delignification efficiency and the β-O-4 content were evaluated. With walnut shells as model feedstock, extraction efficiencies of over 55% were achieved, yielding lignin with a good structural quality in terms of β-O-4 linking motifs (typically over 60 per 100 aromatic units). For example, lignin containing 66 β-O-4 linking motifs was obtained with an 80:20 n-propanol/water ratio, 0.18 M H2SO4 with overall a good extraction efficiency of 57% after 5 h. The majority of the lignin was extracted in the first 2 hours and this lignin showed the best structural quality. Compared to batch extractions, both higher lignin extraction efficiency and higher β-O-4 content were obtained using the flow setup.

Electrospinning Nanofibers from Chitosan/Hyaluronic Acid Complex Coacervates.

Electrospun biopolyelectrolyte nanofibers hold potential for use in a range of biomedical applications, but eliminating toxic chemicals involved in their production remains a key challenge. In this study, we successfully electrospun nanofibers from an aqueous complex coacervate solution composed of chitosan and hyaluronic acid. Experimentally, we investigated the effect of added salt and electrospinning apparatus parameters, such as how applied voltage affected fiber formation. We also studied how the addition of alcohol cosolvents affected the properties of the coacervate solution and the resulting nanofibers. Overall, we observed a trade-off in how the addition of salt and alcohol affected the phase behavior and rheology of the coacervates and, consequently, the size of the resulting fibers. While salt served to weaken electrostatic associations within the coacervate and decrease the precursor solution viscosity, the addition of alcohol lowered the dielectric constant of the system and strengthened these interactions. We hypothesize that the optimized concentration of alcohol accelerated the solvent evaporation during the electrospinning process to yield desirable nanofiber morphology. The smallest average nanofiber diameter was determined to be 115 ± 30 nm when coacervate samples were electrospun using an aqueous solvent containing 3 wt % ethanol and an applied voltage of 24 kV. These results demonstrate a potentially scalable strategy to manufacture electrospun nanofibers from biopolymer complex coacervates that eliminate the need for toxic solvents and could enable the use of these materials across a range of biomedical applications.

Application of Acoustic Spectroscopy to the Characterization of Surfactant Solutions, Emulsions, and Microemulsions: d–Limonene–Water–C12EO7–Isopropanol System

AbstractThe application of acoustic spectroscopy to the characterization of binary C12EO7—water system was studied. It was discovered that the size of micelles in aqueous surfactant solutions could not be determined, but it was possible to determine the size of water nanodomains existing in the surfactant‐rich systems. It was suggested that in colloidal systems, the energy of ultrasonic waves is dissipated only by interfaces existing between condensed phases. The characterization of Winsor transitions by acoustic spectroscopy in water/d‐limonene system stabilized by a mixture of nonionic surfactant and isopropyl alcohol (cosolvent) was also explored. In one study, systems with a constant d‐limonene to water weight ratio obtained in the course of titration of d‐limonene‐in‐water emulsion with increasing amounts of surfactant+alcohol were investigated. In another study, a balanced d‐limonene/water microemulsion was sequentially diluted with water and d‐limonene. The transition between Winsor I and Winsor IV systems was monitored in both cases. Droplet size distributions were calculated using different models for dispersed and continuous phase composition. It was demonstrated that the magnitude of acoustic scattering played a significant role in the ability to reliably determine droplet size distributions, and in particular to simultaneously observe nanometer‐size and micron‐size droplets in Winsor I systems. An attempt was made to account for intrinsic attenuation of surfactant and alcohol by associating them with the aqueous phase, but this approach was shown not to be applicable in the case of Winsor IV microemulsions.