Search Results (266)

To enhance the fire suppression performance of Class A foam, this study identifies sodium dodecyl sulfate (SDS) as the primary foaming agent and develops a high-efficiency foam system comprising primary and auxiliary foaming agents, wetting agents, and foam stabilizers. It interprets these macroscopic findings at the molecular level through molecular dynamics simulations. Sixteen formulations were designed using orthogonal experiments and evaluated in terms of surface tension, viscosity, wetting performance, and foam expansion ratio. The results demonstrated that the formulated systems exhibited superior foaming characteristics compared to conventional aqueous film-forming foam (AFFF), while other physicochemical properties were inferior. Two high-performing foam systems were further investigated using molecular dynamics simulations. Analysis of the spatial concentration distributions, diffusion coefficients, and the hydrogen-bonding networks of water molecules revealed 14.3% and 14.2% increases in the peak values of the radial distribution function (RDF) for the two systems modified with auxiliary foaming agents, respectively. The auxiliary foaming agents exhibited synergistic effects with SDS, enhancing its water activation capability. The incorporation of wetting agents reduced the water diffusion coefficients by 4.7% and 21.9%, indicating that sodium bis(2-ethylhexyl) succinate sulphonate (T) interferes less with the primary foaming agent than alcohol ethoxylate (AEO). The selected formulations also demonstrated 4.4% and 3.5% reductions in water hydrogen bonding compared to SDS-only solutions, indicating decreased molecular cohesion and improved water activation. By integrating physicochemical evaluation with molecular simulation, the optimized formulation was determined to be SDS (primary foaming agent), sodium fatty alcohol ether sulfate (auxiliary foaming agent), alcohol ethoxylate (wetting agent), lauryl hydroxysultaine (foam stabilizer), and ethylene glycol butyl ether (cosolvent). Full article

This paper shows that low concentrations of either a low-molecular-weight or a recyclable polymeric cosolvent can be used to design recyclable, tunable alkane polymeric solvent systems. We have shown that dyes experience a microheterogeneous environment that is ca. 40–50% like that of a polar solvent with as little as 0.1 M added cosolvent. Dyes like Nile red or a polyisobutylene (PIB)-bound dansyl fluorophore both detected microheterogeneity in macrohomogeneous mixtures of heptane or a poly(α-olefin) (PAO) with 0.1–2.0 M added polar solvents. H-Bonding cosolvents have greater effects than cosolvents that only interact with dyes by dipole–dipole interactions. Microheterogeneity was also seen when a PIB-bound version of a low-molecular-weight solvent is used as the added polar cosolvent. These microheterogeneous environments can advantageously be used in synthetic and catalytic reactions. This was demonstrated in transesterification and S_N2 chemistry. Reactions in PAO solutions polarized by 2 M added THF or by 0.5 M of a PIB-bound HMPA analog both had enhanced reactivity versus reactions in a PAO solution without added cosolvent. In the latter case, the catalyst, the PAO solvent, and the PIB-bound cosolvent were all fully recyclable. Full article

Interfacial polymerization (IP) has been widely utilized to synthesize composite membranes. However, precise control of this reaction remains a challenge due to the complexity of the IP process. Herein, an optical three-dimensional microscope was used to directly observe the IP process. To construct copolyesteramide containing phthalazine moiety films, rigid monomer 4-(4′-hydroxyphenyl)-2,3-phthalazin-1-one (DHPZ) and flexible monomer piperazine (PIP) were used as aqueous phase monomers, and trimesoyl chloride (TMC) served as the organic phase monomer. Multilayer cellular structures were observed for the copolyesteramide films during the IP process. The effects of multiple factors including the ratio between flexible and rigid monomers, co-solvents, and the addition of phase transfer catalysts on the film growth and the morphologies were investigated. This research aims to deepen our understanding of the IP process, especially for the principles which govern polymer film growth and morphology, to promote new methodologies for regulating interfacial polymerization in composite membrane preparation. Full article

Albumin-based nanoparticles are promising drug delivery systems due to their biocompatibility, biodegradability, and ability to improve targeted drug release. Among various preparation methods, radiation-induced cross-linking in the presence of ethanol has been proposed in the literature as an effective method for producing protein nanoparticles with preserved bioactivity and controlled size. However, the mechanisms by which ethanol radicals contribute to protein aggregation remain insufficiently understood. In this study, we investigate the role of ethanol in the aggregation of albumins to determine whether its presence is necessary or beneficial for nanoparticle formation. Using pulse radiolysis, spectroscopy methods, resonance light scattering (RLS), and near-infrared (NIR) spectroscopy, we examined aqueous ethanol solutions of albumins before and after irradiation. Our results show that ethanol concentrations above 40% (v/v) significantly promote both radiation-induced and spontaneous protein aggregation. Mechanistic analysis indicates that ethanol radicals react with albumin similarly to hydrated electrons, mainly targeting disulfide bridges. This reaction leads to the formation of sulfur-centered radicals and the formation of intermolecular disulfide bonds that stabilize protein nanostructures by excluding the formation of dityrosine bridges, as described in the literature. In contrast, ethanol concentration below 40% does not favor the radiation-induced aggregation compared to the solution containing t-BuOH. These results provide novel insights into the role of organic cosolvents in protein aggregation and contribute to a broader understanding of the mechanisms of formation of albumin-based nanoparticles using ionizing radiation. Full article

This study investigates the sequential extraction of lipids and saponins from C. frondosa viscera. Lipids were extracted using supercritical carbon dioxide (scCO₂) in the presence of ethanol (EtOH) as a co-solvent. Subsequently, the lipid-extracted viscera underwent three saponin extraction approaches, scCO₂-scCO₂, scCO₂-EtOH, and scCO₂-hot water, resulting in saponin-rich extracts. Process parameter investigation for saponin extraction from scCO₂-defatted viscera revealed minimal effects of temperature, pressure, extraction time, static extraction, and EtOH concentration on saponin yields, allowing for milder operational conditions (35 °C, 20 MPa, 30 min dynamic extraction, 75% EtOH at 0.5 mL/min) to achieve energy-efficient recovery. Continuous EtOH feeding predominates the scCO₂ extraction of saponins. The sequential scCO₂ extraction of lipid and saponins yielded saponins at 9.13 mg OAE/g, while scCO₂ extraction of lipid followed by a 24 h 70% EtOH extraction of saponins achieved 16.26 mg OAE/g, closely matching the optimized ultrasonic-assisted extraction of saponins (17.31 mg OAE/g) from hexane-defatted samples. Antioxidant activities of saponin-rich extracts obtained in the sequential scCO₂-EtOH extraction (17.12 ± 4.20% DPPH scavenging) and the sequential scCO₂-scCO₂ extraction (16.14 ± 1.98%) were comparable to BHT (20.39 ± 0.68%), surpassing that of hexane-defatted ultrasonic extracts (8.11 ± 1.16%). The optimized scCO₂-EtOH method offers a sustainable alternative, eliminating toxic solvents while maintaining high saponin yields and bioactivity. Full article

This study investigated the use of supercritical carbon dioxide (CO₂) to extract bioactive compounds from Thai fingerroot (Boesenbergia rotunda), focusing on the effects of pressure, temperature, CO₂ flow rate, and ethanol co-solvent concentration. A central composite design within a response surface methodology framework was employed to optimize the total extraction yield, total phenolic content (TPC), and total flavonoid content (TFC). Conventional ethanol maceration was used as a benchmark. High-performance liquid chromatography identified the major compounds in the extracts, such as pinostrobin and pinocembrin. The results showed that the yield, TPC, and TFC increased with higher pressure, CO₂ flow rate, and co-solvent levels, whereas higher temperatures had a negative effect (p ≤ 0.05). Interactions between pressure and temperature favored the yield and TPC but not TFC. The optimal conditions—250 bar, 45 °C, 3 L/min CO₂ flow rate, and 100% ethanol—produced a yield of 28.67%, TPC of 354.578 mg GAE/g, and TFC of 273.479 mg QE/g. These values exceeded those obtained using conventional extraction (9.91% yield, 332.86 mg GAE/g TPC, and 77.57 mg QE/g TFC at 60 min). The regression models showed strong predictive accuracy (R² > 0.9). Pinostrobin and pinocembrin were the dominant phenolic compounds. These findings demonstrate the superior efficiency of supercritical CO₂ extraction for isolating phenolic compounds from B. rotunda. Full article

Background: Solubility is a fundamental physicochemical property in pharmaceutical, chemical and environmental industrial processes. Regarding Triclocarban (TCC), a broad-spectrum antimicrobial, solubility is particularly challenging due to its low aqueous solubility and hydrophobic nature; these challenges can be addressed by some effective techniques such as cosolvency, which allows one to increase the solubility of drugs by several orders of magnitude. This study aims to thermodynamically evaluate the solubility of TCC in cosolvent mixtures of PEG 200 + water at different temperatures. Methods: Experimental solubility data were determined using the shake-flask followed by UV quantification analysis at saturation methods, and thermodynamic functions of the solution processes were calculated using the Gibbs–van’t Hoff–Krug model. Results: The solubility results demonstrate the positive cosolvent effect of PEG 200 on the solubility of TCC, whose solution process is thermodynamically strongly governed by the enthalpy of solution with entropic preference in PEG 200-rich mixtures. Conclusions: The solubility of TCC is an endothermic, thermo-dependent process. The addition of PEG 200 to the cosolvent mixture favors this process and shows a positive cosolvent effect. Full article

Per- and polyfluoroalkyl substances (PFASs) are a family of synthetic chemicals that were used to improve the quality of several commercial products by making them resistant to heat, oil, stains, and grease. By containing a fluorinated carbon tail and a hydrophilic head (-COOH, -SO₃H), PFASs act as surfactants that are attracted to bubble–water interfaces. Foam fractionation is the process of facilitating PFAS–air bubble interactions for the purpose of removing contaminants from tainted water. In this paper, we report on the use of foam fractionation and electrochemical oxidation (EO) under stirred batch conditions (200 mL) to remediate PFAS-contaminated water. We used radiolabeled PFOA (perfluorooctanoic acid; ¹⁴C-PFOA) as a representative surrogate to quickly screen treatment variables of flow rate, pH, temperature, and soap mass. Using radiolabeled PFASs eliminated the possibility of cross-contamination and greatly reduced analytical costs and processing time. The results showed that foam fractionation can remove 80 to 90 percent of PFOA from water within 30 min and that 90 to 100 percent of the PFOA in the concentrated foamate can be oxidized via electrochemical oxidation (-¹⁴COOH → ¹⁴CO₂). We also tested the efficacy of the combined foam fractionation–EO treatment in natural waters by spiking ¹⁴C-PFOA and a cosolvent (CTAB) into PFAS-contaminated water obtained from two field sites with divergent PFAS concentrations and differing sources of PFAS contamination (natural drainage ditch vs. WWTP). Using a larger-scale tank (3500 mL), we observed that foam fractionation was 90% effective in removing ¹⁴C-PFOA from the WWTP effluent but only 50% effective for the drainage ditch water. Regardless, EO was highly effective in oxidizing ¹⁴C-PFOA in the foamate from both sources with half-lives (T_1/2) ranging from 8.7 to 15 min. While water chemistry differences between source waters may have influenced foam fractionation and require additional investigations, tank experiments provide the first proof-of-concept experiment using ¹⁴C-PFASs that foam fractionation and electrochemical oxidation can be used in tandem to treat PFAS-contaminated water. Full article

β-Galactosidase, a glycoside hydrolase enzyme, also possesses glycosyl transferase activity and can glycosylate various aglycones, including tyrosol, a phenylethanoid with antioxidant and health-promoting effects. This study examines the effect of lactose, tyrosol and deep eutectic solvents (DESs) as co-solvents on the stability and activity of Aspergillus oryzae β-galactosidase during the enzymatic synthesis of tyrosol β-d-galactoside (TG). The enzyme’s thermal stability was assessed using nanoDSF and circular dichroism spectroscopy, while the enzyme’s activity and specificity toward different glycosyl acceptors were investigated using the initial rate method. The effects of tyrosol and DESs on tyrosol galactoside synthesis over a 6 h period were also studied. Lactose and glycerol were found to stabilize the enzyme. Among the DESs tested, those containing betaine showed the highest stabilizing effect. The presence of DESs not only affected the overall enzyme activity but also changed the enzyme specificity, most frequently in favor of lactose hydrolysis. Components of DESs containing alcohol groups (polyols) also acted as transglycosylation acceptors. However, both glycerol and tyrosol were found to inhibit overall enzyme activity and TG synthesis. Overall, our findings provide new and valuable insights into the influence of reaction conditions on the stability and specificity of β-galactosidase. Full article

This study evaluated the acute and developmental toxicity of selected hydrotropes, co-solvents, and surfactants commonly used in pharmaceutical and cosmetic formulations, using Artemia salina as a model organism. Two bioassays were employed: a lethality test and a hatching inhibition test. Compounds such as sodium lauryl sulfate (LC₅₀ < 0.05%), sodium xylenesulfonate (LC₅₀ = 0.79%), sodium p-toluensulfonate (LC₅₀ = 0.21%), N,N-dimethylbenzamide (LC₅₀ < 0.05%), and N,N-diethylnicotinamide (LC₅₀ = 0.05%) exhibited high toxicity at 48 h, inducing significant mortality and strong inhibition of hatching. Glycerin, propylene glycol, and dimethyl sulfoxide showed low toxicity across all concentrations. Lethal concentration values confirmed the high toxicity of sodium xylenesulfonate and N,N-dimethylbenzamide, with moderate effects observed for other compounds. The hatching inhibition test proved more sensitive than the lethality test, enabling the detection of embryotoxicity and developmental delays. Although more laborious, it provided detailed information into how the tested substances influenced developmental stage progression. Hierarchical clustering analysis grouped the substances based on toxicity patterns and clearly discriminated highly toxic surfactants from low-toxicity solvents. The results demonstrated that combining both bioassays offers a more comprehensive evaluation of toxicity, with the hatching test being particularly useful for identifying early developmental effects not evident in lethality testing alone. Full article

The effects of proline co-solvent on helix folding are explored through the single discrete coordinate of the number of helical hydrogen bonds. The analysis is based on multi-microsecond length molecular dynamics simulations of alanine-based helix-forming peptides, (ALA)n, of length n = 4, 8, 15 and 21 residues, in an aqueous solution with 2 M concentration of proline. The effects of addition of proline on the free energy landscape for helix folding were analyzed using the graph-based Dijkstra algorithm, Optimal Dimensionality Reduction kinetic coarse graining, committor functions, as well as through the diffusion of the helix boundary. Viewed at a sufficiently long time-scale, helix folding in the coarse-grained hydrogen bond space follows a consecutive mechanism, with well-defined initiation and propagation phases, and an interesting set of intermediates. Proline addition slows down the folding relaxation of all four peptides, increases helix content and induces subtle mechanistic changes compared to pure water solvation. A general trend is for transition state shift towards earlier stages of folding in proline relative to water. For ALA5 and ALA8 direct folding is dominant. In ALA8 and ALA15 multiple pathways appear possible. For ALA21 a simple mechanism emerges, with a single path from helix to coil through a set of intermediates. Overall, this work provides new insights into effects of proline co-solvent on helix folding, complementary to more standard approaches based on three-dimensional molecular structures. Full article

Addressing the critical challenges of interfacial defects and insufficient stability in perovskite solar cells, this work introduces a co-solvent engineering strategy to dynamically regulate the phenethylammonium chloride (PEACl) passivation layer. The effect of isopropyl alcohol (IPA) and a DMSO: IPA (1:100) mixture as solvent for forming the PEACl 2D passivation layer is systematically explored, and the synergistic interplay between solvent coordination strength and crystallization kinetics is systematically investigated. The DMSO: IPA (1:100) blend balances Pb-O coordination (via DMSO) and rapid phase separation (via IPA), enabling the oriented growth of a dense, ultrathin 2D perovskite overlayer. This suppresses defect density (electron traps reduced to 1.68 × 10¹⁵ cm⁻³) and extends carrier lifetime, yielding a champion power conversion efficiency (PCE) of 24.27%—a significant improvement over the control (22.73%). For the first time, we establish a dual-parameter “solvent coordination-crystallization kinetics” model, providing a universal framework for designing environmentally benign solvent systems and advancing the industrial scalability of high-performance perovskite solar cells (PSCs). Full article

Localized high-concentration electrolytes (LHCEs) are promising systems for improving the high-voltage performance and interfacial stability of lithium-metal batteries (LMBs). Unfortunately, they are always challenged by liquid–liquid phase separation during solution preparation. Further investigation is always required when the prepared electrolyte has encountered liquid–liquid phase separation previously. Here, we propose a “cognate cosolvent” strategy to mediate phase-separated LiBF₄/fluoroethylene carbonate (FEC)|ethyl trifluoroacetate (TFAE) mixtures with ethyl acetate (EA), forming effective LiBF₄/FEC/EA/TFAE-based LHCEs (B-LHCEs). Because of their unique solvation structure, the B-LHCEs exhibit high oxidative stability, facilitating Li⁺ transport. The optimized B-LHCEs help single-crystal LiMn_0.8Mn_0.1Co_0.1O₂/Li batteries form robust interphases, improving interfacial stability. As a result, distinct performance can be obtained (4.5 V, 500 cycles, ~90%, 1400, ~70%; 25 C, 128 mAh g⁻¹, 4.7 V, 500, 82.5%). This work turns the “impossible” into an “effective” high-voltage electrolyte design, transcending the previous paradigms of electrolyte investigation and enriching LHCE preparation research. Full article

In seeking alternatives for reducing environmental damage, fabricating filtration membranes using biopolymers derived from agro-industrial residues, such as cellulose acetate (CA), partially dissolved with green solvents, represents an economical and sustainable option. However, dissolving CA in green solvents through mechanical agitation can take up to 48 h. An ultrasonic probe was proposed to accelerate mass transfer and polymer dissolution via pulsed interval cavitation. Additionally, ultrasound-assisted phase inversion (UAPI) on the external coagulation bath was assessed to determine its influence on the properties of flat sheet and hollow fiber membranes during phase inversion. Results indicated that the ultrasonic pulses reduced dissolution time by up to 98% without affecting viscosity (3.24 ± 0.06 Pa·s), thermal stability, or the rheological behavior of the polymeric blend. UAPI increased water permeability in flat sheet membranes by 26% while maintaining whey protein rejection above 90%. For hollow fiber membranes, UAPI (wavelength amplitude of 0 to 20%) improved permeability by 15.7% and reduced protein retention from 90% to 70%, with MWCO between 68 and 240 kDa. This report demonstrates the effectiveness of ultrasonic probes for decreasing the dissolution time of dope solution with green cosolvents and its potential to change the structure of polymeric membranes by ultrasound-assisted phase inversion. Full article

The incorporation of essential oils into the oil phase of oil-in-water microemulsions is an emerging strategy for the development of stable water-based topical formulations. The introduction of a suitable polymer to formulate film-forming microemulsions may improve topical administration; however, the effect of formulation variables on film quality attributes has not been studied. In this study, thermodynamically stable microemulsion concentrates consisting of surfactant (Kolliphor^® RH40), alone or in combination with cosurfactant Transcutol^® at surfactant-to-cosurfactant mass ratio 7:3, cosolvent (propylene glycol), and synthetic oils (medium-chain triglycerides or isopropyl myristate) with tea tree, cinnamon, or thyme essential oil were formulated and diluted with hypromellose solution in a water/isopropanol mixture (1:1 w/w) to produce film-forming microemulsions. The type and concentration of synthetic and essential oils and cosurfactant influenced the dynamics of structural transformations upon dilution as well as the rheological behavior, viscosity, and pH of film-forming microemulsions. Films obtained by casting film-forming microemulsions were opalescent, smooth, flexible, and swellable in artificial sweat and water. The weight and yield of films increase with the synthetic oils present and without cosurfactant added. Optimizing the ratio of essential oil/synthetic oil, the type of synthetic oil, and the inclusion/exclusion of cosurfactant allows for achieving the targeted film attributes for cosmetic and pharmaceutical applications, including wound treatment. Full article