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Thermophoresis has emerged as a powerful tool for characterizing and manipulating colloids at the nano- and micro-scales due to its sensitivity to colloid–solvent interactions. The use of surfactants enables the tailoring of surface chemistry on colloidal particles and the tuning of interfacial interactions. However, the microscopic mechanisms underlying thermophoresis in surfactant solutions remain poorly understood due to the complexity of multiscale interaction coupling. To achieve a more fundamental understanding of the roles of surfactants, we investigated the thermophoretic behavior of silica beads in both ionic and nonionic surfactant solutions at various background temperatures. We provide a complete mechanistic picture of the effects of surfactants on interfacial interactions through mode-coupling analysis of both electrophoretic and thermophoretic experiments. Our results demonstrate that silica thermophoresis is predominantly governed by the dissociation of silanol functional groups at silica–water interfaces in nonionic surfactant solutions, while in ionic surfactant solutions, the primary mechanism driving silica thermophoresis is the adsorption of ionic surfactants onto the silica surface. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40–50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing. Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM. The underlying mechanism governing this unusual behavior is revealed and is shown to relate to the mono- to di-esters ratio in the solutions. Solutions primarily containing sucrose monoesters (monoesters molecules ≳ 98% of all surfactant molecules) exhibit behavior typical of nonionic surfactants, with minimal changes with temperature. In contrast, the coexistence of mono- and di-esters results in the formation of discrete monodisperse diester particles and a network of partially fused diester particles at low temperature. As the temperature approaches the diesters' melting point, wormlike mixed micelles form, causing a viscosity peak. The height of this peak increases significantly with the diester concentration. Further temperature increase leads to fluidization of surfactant tails and formation of branched micelles, while excess diester molecules phase separate into distinct droplets. [ABSTRACT FROM AUTHOR]

Cloud point (CP) of aqueous solution of metformin hydrochloride (MNH) and triton X-100 (TX-100) was examined in presence of several alcohols (MeOH, EtOH, 1-PrOH, 2-PrOH, and 1-BuOH). The main focal point of this study was to evaluate the cloud development for the combination of TX-100 and MNH, as well as to indicate the mode of how various alcohols influence both the physicochemical parameters and interaction forces of that mixture. The cloud point (CP) measurement technique was chosen because of its broad applicability in both the medical and industrial sectors. As alcohol contents increased, higher CP values of TX-100 and MNH mixture were observed except in aq. 1-BuOH (CP is decreased). In the aqueous alcoholic medium (above 3000 mmol·kg−1), the phase separation of TX-100 (92.7 mmol·kg−1) and MNH (2 mmol·kg−1) mixture showed the subsequent trend: CP (H2O + 2-PrOH) ˃ CP (H2O + MeOH) > CP (H2O + EtOH) ˃ CP (H2O + 1-PrOH). It was observed that the depth to which alcohol molecules penetrate micelles is influenced by the length of the alcohol chain. Longer hydrophobic alcohol molecules have the ability to impair more ethylene oxide–water (EO-water) interactions by penetrating deeper into the micelle's palisade layer. As a result, there is more occurrence of dehydration, which promotes the production of micellar particles as well as lowers the cloud point substantially. The calculated Δ G c 0 values of the TX-100 + MNH mixture in alcohols media are appeared as positive in every scenario examined, proving that the clouding procedure is not spontaneous. The positive Δ G c 0 results might be attributed to the surfactant's surface layer in forming H-bond via the water molecules. A decrease in the positive Δ G c 0 values is evidenced by a rise in alcohol concentrations. Consequently, there is less non-spontaneity at higher alcohol concentrations. The + Δ H c 0 (endothermic) and + Δ S c 0 magnitudes are detected in aq. MeOH, EtOH, and 2-PrOH solutions. However, Δ H c 0 and Δ S c 0 magnitudes are found as positive (endothermic) and negative (exothermic) at lower and higher contents of 1-PrOH solution while the opposite trend in the Δ H c 0 and Δ S c 0 was detected in aq. 1-BuOH solution. Possible interactions among TX-100 and metformin hydrochloride in aqueous 1-BuOH media [ABSTRACT FROM AUTHOR]

Combinatorial chemistry and drug design have produced more lipophilic, heavier, and less water soluble drugs in recent years. It is more difficult to find the best drug delivery system for them. In this area of technology and drug development, new strategies are applied to develop novel drug moieties and improve their water solubility. One of the main obstacles is the use of poorly water soluble chemicals in formulation. Beta-ionone (β-ionone) is utilised to target many forms of cancer and has been shown to have anticancer potential in recent studies, however it has poor water solubility. The goal of the current study was to enhance the solubility of beta-ionone using various carrier materials like non-ionic water-dispersible surfactant Gelucire® 50/13 (polyoxylglycerides) which self-emulsifies in aqueous media forming a fine micro-dispersion. Another amphiphilic material, Soluplus® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer was used to enhance the solubility of beta-ionone. Further, Hydroxypropyl-β-Cyclodextrin inclusion complex was also prepared and evaluated to check the improvement in the solubility of beta-ionone. Finally, the performance of these carries was checked by developing the pellet formulation. An appropriate formulation offers a method to improve the solubility, dissolution, and bioavailability of β-ionone. When compared to alternative cancer treatment options, this formulation may aid to improve patient compliance and the drug's effectiveness. The pellet formulation developed utilising HP-β-CD has produced outstanding results and may be more stable due to the inclusion-capabilities, complexes. [ABSTRACT FROM AUTHOR]

Nanoemulsions are kinetically stable emulsions with droplet size distribution in the range of 10–500 nm. Low interfacial tension (IFT), small droplet size, and wettability alteration properties of nanoemulsions have led to their application for enhanced oil recovery (EOR) EOR. The current study deals with the formulation and characterization of Tergitol 15-S-9 surfactant stabilized oil/water nanoemulsion (NE). Optimal surfactant concentration accompanied by optimal salinity determination was done by observing long-term stability. The stability of the nanoemulsions was analyzed by Turbiscan and Zeta potential analysis. The optimal nanoemulsion was characterized in terms of droplet size, rheology, wettability, miscibility, and IFT. All the prepared nanoemulsion showed particle size < 300 nm. optimized nano emulsion, that is, 0.5 wt.% surfactant +0.5 wt.% salinity showed good IFT reduction and wettability alteration capability. Nanoemulsion also showed good miscibility behavior with actual crude oil at 60 °C. Rheology of the formed emulsion shows a mixed nature that is shear thinning as well as shear thickening nature which is favorable for heterogeneous reservoirs. Core-flooding experiments were conducted at optimized nanoemulsion formulation, and additional oil recovery of 13.93% of the original oil in place was obtained after the conventional water flooding. Highlights: Experimental and mechanistic investigation of nanoemulsions for oil recovery. Enhanced miscibility of Tergitol 15-S-9 stabilized nanoemulsion with crude oil. Viscosity enhancement by macromolecular and supramolecular network structures. Low IFT achieved for the nanoemulsion resulting enhanced oil displacement. Encouraging oil displacement by injection of formulated nanoemulsion. [ABSTRACT FROM AUTHOR]

The present study explores the cleaning efficacy of a set of nonionic surfactants (linear ethoxylated alcohol, secondary ethoxylated alcohols with 5, 7, and 9 ethoxy groups, glycoside surfactants, polyglycerol surfactants, and an ethoxylated sorbitan monolaurate) combined with cationic biocides—alkyl quaternary ammonium salts. A simple hard surface cleaning methodology was applied, which was shown to discriminate well between poor and good cleaning formulations. In addition to cleaning efficacy, surface aesthetics such as gloss and haze were evaluated together to assess surface streaking caused by a residual surfactant layer. The haziness determination turned out to be the key feature revealing the complex cleaning performance of multi‐component products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cryo-electron tomography was used to determine the structural characteristics of complicated surfactant aggregates. • Transitions branched WLMs → saturated network of WLMs → perforated vesicles were observed in solutions of zwitterionic and nonionic surfactants. • Transformations proceed through an increase in the number of branches at the expense of cylindrical subchains and semispherical endcaps. • Exponential distribution of subchains length was confirmed experimentally for multiconnected saturated networks. • Perforated vesicles were observed when the length of subchains became much shorter than the persistence length. The formation of micellar aggregates and the changes in their morphology are crucial for numerous practical applications of surfactants. However, a proper structural characterization of complicated micellar nanostructures remains a challenge. This paper demonstrates the advances of cryo-electron tomography (cryo-ET) in revealing the structural characteristics that accompany the evolution of surfactant aggregates. By using cryo-ET in combination with cryo-transmission electron microscopy (cryo-TEM), small-angle neutron scattering (SANS), and rheometry, studies were carried out on a model system composed of zwitterionic and nonionic surfactants. In this system, the molecular packing parameter was increased gradually by increasing the molar fraction of nonionic surfactant. A series of structural transformations was observed: linear wormlike micelles (WLMs) → branched WLMs → saturated network of multiconnected WLMs → perforated vesicles (stomatosomes). The transformations occur through an increase in the number of branches at the expense of cylindrical subchains and semispherical endcaps. Exponential distribution of subchains length was confirmed experimentally for multiconnected saturated networks. The stomatosomes were formed when the length of subchains becomes much shorter than the persistence length, causing the three-dimensional (3D) structure to transform into a two-dimensional (2D) membrane. This work identifies the mechanism of the structural changes, which can be further used to design various surfactant self-assemblies. [ABSTRACT FROM AUTHOR]

[Display omitted] Nonionic surfactants can counter the deleterious effect that anionic surfactants have on proteins, where the folded states are retrieved from a previously unfolded state. However, further studies are required to refine our understanding of the underlying mechanism of the refolding process. While interactions between nonionic surfactants and tightly folded proteins are not anticipated, we hypothesized that intermediate stages of surfactant-induced unfolding could define new interaction mechanisms by which nonionic surfactants can further alter protein conformation. In this work, the behavior of three model proteins (human growth hormone, bovine serum albumin, and β-lactoglobulin) was investigated in the presence of the anionic surfactant sodium dodecylsulfate, the nonionic surfactant β-dodecylmaltoside, and mixtures of both surfactants. The transitions occurring to the proteins were determined using intrinsic fluorescence spectroscopy and far-UV circular dichroism. Based on these results, we developed a detailed interaction model for human growth hormone. Using nuclear magnetic resonance and contrast-variation small-angle neutron scattering, we studied the amino acid environment and the conformational state of the protein. The results demonstrate the key role of surfactant cooperation in defining the conformational state of the proteins, which can shift away or toward the folded state depending on the nonionic-to-ionic surfactant ratio. Dodecylmaltoside, initially a non-interacting surfactant, can unexpectedly associate with sodium dodecylsulfate-unfolded proteins to further impact their conformation at low nonionic-to-ionic surfactant ratio. When this ratio increases, the protein begins to retrieve the folded state. However, the native conformation cannot be fully recovered due to remnant surfactant molecules still adsorbed to the protein. This study demonstrates that the conformational landscape of the protein depends on a delicate interplay between the surfactants, ultimately controlled by the ratio between them, resulting in unpredictable changes in the protein conformation. [ABSTRACT FROM AUTHOR]

This research investigates the impact of gamma irradiation on epoxy-MWCNT nanocomposites for satellite deployment mechanisms. Nanocomposites, enhanced with surfactants, were meticulously prepared and subjected to controlled gamma irradiation (250–1000 kGy) utilizing the Cobalt-60 facility Industrial Mega Gamma-1 at NCRRT in Egypt. Surface tension measurements explored surfactant effects on epoxy-MWCNT composites in acetone. Acetone reduced tension from 26.7 to be 24.2 (mN/m). Surfactants (Tween 80, SDS) effectively lowered tension (24.4 mN/m), while surfactant-free systems had higher tension (25.1 mN/m). Cationic surfactant (CTAB) slightly increased tension (25.4 mN/m) but aided MWCNT dispersion. Nonionic and anionic surfactants showed superior dispersing power, aligning with MWCNTs and enhancing dispersion. Thermogravimetric analysis (TGA) unveiled alterations in the thermal stability of epoxy-MWCNT nanocomposites induced by radiation, particularly evident at elevated doses (500 and 1000 kGy). Notably, surfactant-modified specimens exhibited discernible effects on various thermal stability parameters. DMA analysis revealed radiation-induced changes in viscoelastic properties. Unirradiated epoxy exhibited a Tg of 58 °C, while 250 kGy irradiation enhanced crosslinking (Tg: 64 °C). Higher doses (500 kGy, 1000 kGy) caused marginal Tg changes. Surfactant-modified samples showed varied effects, with Tween 80 emphasizing its role in phase separation. Results highlighted radiation's influence on stiffness and energy dissipation. Shape memory behavior indicated increased recovery time with higher doses, except at 250 kGy. Epoxy-MWCNT exhibited a stable recovery time, suggesting a MWCNT stabilizing effect. Fixation rates consistently reached 100%, indicating improved shape recovery influenced by MWCNTs and surfactants. This study provides insights into optimizing nanocomposites for satellite deployment applications. [ABSTRACT FROM AUTHOR]

The conditions for the smart colorimetric determination of cetylpyridinium chloride and sodium dodecyl sulfate by reaction with Coomassie brilliant blue G (CBBG) have been proposed. The nature of the absorption and fluorescence spectra of aqueous solutions of CBBG as a function of acidity has been investigated. A variety of reagent forms and associations with ionic surfactants have been demonstrated. The composition of the associates formed in the CBBG–cationic surfactant system has been established. The increase in the analytical signal of the cationic surfactant and the stabilization of the colloid-chemical state of the system during reactions in the organized medium of the nonionic surfactant Triton X-100 has been demonstrated. These effects are realized through association in premicellar solutions and as a result of the solubilization of components in Triton X-100 micellar solutions. The addition of long-chain cationic surfactants to the reagent occurs with the replacement of the heteroatom proton. The absorption of CBBG–cationic surfactant associates solutions increases with the length of the cationic surfactant hydrocarbon chain. Ethanol additives decrease the aggregation of CBBG. The technique of cationic surfactant determination has been tested in the analysis of the pharmaceutical. The results show that the simplicity of analytical signal registration with satisfactory correctness and acceptably high sensitivity of determination is an advantage of the developed technique. [ABSTRACT FROM AUTHOR]

In this study, the lavender essential oil-incorporated polylactic acid (PLA) nanofibers were fabricated by the electrospinning technique with the presence of kolliphor as a nonionic surfactant. The FTIR spectra supported the chemical composition of the fibers. The FTIR spectra demonstrated that there is no chemical reaction present between PLA and lavender essential oil. The SEM images of all nanofibers showed bead-free morphology. ImageJ results showed that the average diameter of lavender oil-loaded fibers ranged between 121.6 ± 32 and 228.2 ± 53 nm. All lavender essential oil-incorporated nanofibers were hydrophobic with satisfactory thermal properties. Furthermore, the lavender essential oil-incorporated PLA nanofibrous mats exhibited good antioxidant activity. The results showed that as the concentration of the essential oil in resulting nanofibers increased, the antioxidant activity also increased. According to the results of this study, lavender essential oil-loaded PLA fibers can be considered for a wide range of potential applications such as active packaging, food coating, facial masks, and wound dressing. [ABSTRACT FROM AUTHOR]

Semi-volatile organic pollutants were found in most organic contaminated sites, especially in the industrial production of plastic and paint products, dismantling of electronic wastes, production of organic solvents, and chemical coatings. Electrokinetic remediation (EKR) was recognized as critical method to resolve the problem of organic pollutants separation and degradation. However, the low efficiency desorption and migration of organic pollutants was the main concerns during EK remediation. In this study, cyclododecane (CDD) was selected to investigate the process of electroosmotic flushing with anionic surfactant (sodium dodecyl sulfate, SDBS) and non-ionic surfactants (alcohol ethoxylate, AEO) for facilitating chemical desorption of low boiling point organic pollutants from soil. Simulated contaminated soil was subjected to treatment in an EK cell at 1 V/cm for 7 days. The experimental dependent variables, such as current, electroosmotic flow (EOF), pH, electrical conductivity (EC), and the concentration of CDD in the contaminated soil were continuously monitored. The results revealed that both current and EOF exhibited the trend of SDBS (13.74 mA, 350.9 mL) > water (8.22 mA, 285.7 mL) > AEO (6.12 mA, 124.3 mL). Furthermore, the removal efficiency of CDD by surfactants also followed this order with corresponding percentages of 90.87% and 90.01%. The soil pH near the cathode increased, and it caused alkalization trend of the flowing soil solution and improvement of CDD removal rate. Conversely, the lowest EC value was observed in the middle of the soil chamber. The highest overall CDD removal rate was achieved by employing a strategy of surfactant-assisted electrokinetic remediation, and approximately 90% CDD was transfered to the liquid phase. These findings contribute to our understanding of spatial and temporal variations in pollutant removal and the interplay between different electrokinetic variables during EK remediation. [ABSTRACT FROM AUTHOR]

Natural biopolymers become increasingly attractive as bio-based alternatives to petrol-based rheological modifiers, especially in personal care applications. However, many polysaccharides exhibit undesired properties in cosmetic applications such as limited viscosifying characteristics, unpleasant sensory properties, or incompatibility with certain formulation compounds. Here, a comprehensive rheological analysis of non-decorated acetan-like heteroexopolysaccharides derived from two Kozakia baliensis strains was performed in selected surfactant formulations. The results were compared to native xanthan gum and a genetically engineered xanthan variant, Xan∆ gumFGL , which lacks any acetyl- and pyruvyl moieties and whose rheological properties are unaffected by saline environments. All four polysaccharides displayed a highly similar rheological performance in the non-ionic surfactant lauryl glucoside, while the rheological properties differed in amphoteric and anionic surfactants cocamidopropyl betaine and sodium laureth sulfate due to minor changes in side chain composition. Polysaccharide precipitation was observed in the presence of the cationic surfactant. Nevertheless, the native heteroexopolysaccharide derived from K. baliensis LMG 27018 shows significant potential as a salt-independent rheological modifier compared to the genetically engineered Xan∆ gumFGL variant. In addition, blends of heteroexopolysaccharides from K. baliensis and several galactomannans displayed synergistic effects which were comparable to native xanthan gum-galactomannan blends. This study shows that heteroexopolysaccharides of K. baliensis are capable of further extending the portfolio of bio-based rheological modifiers. [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Museum of Sun Yat-sen University houses a collection of antique glass slides dating back to the 1940s. These historical artifacts not only serve as a record of the past but also bring history to life. During extended storage, the emulsion layer on glass slides may harden and become brittle, leading to cracking and buckling. This study suggests a method to enhance the physical property of the emulsion layer by using a combination of nonionic surfactant isomeric alcohol ethoxylates eight (TO-8) and waterborne epoxy resin (WER). We investigated the microscopic action mechanism of the two on the emulsion layer of glass slides using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), water contact angles, and other techniques. Our study revealed that TO-8 can significantly eliminate the spherulitic crystal structure of the emulsion layer, as well as improve its softness and hydrophilicity. The addition of the WER ensures that the cracking and warping of the emulsion layer film is fully corrected, resulting in a flat surface. Additionally, the size of the emulsion layer film remains stable even after wetting. The WER has minimal impact on the image information of glass slides. The emulsion layer of the glass slides, restored using the softening protection solutions developed in this study, showed almost full recovery of image information. This research holds significant theoretical and practical value for repairing cracked and warped emulsion layers on glass slides. [ABSTRACT FROM AUTHOR]

Triacontanol is a long-chain primary alcohol derived from policosanol, known for its diverse biological activities, including functioning as a plant growth regulator and exhibiting anti-inflammatory and antitumoral effects. However, its application is limited due to its high hydrophobicity, resulting in poor absorption and reduced therapeutic effectiveness. A potential solution to this problem is the use of niosomes. Niosomes are carriers composed of non-ionic surfactants, cholesterol, charge-inducing agents, and a hydration medium. They are effective in encapsulating drugs, improving their solubility and bioavailability. The objective of this study was to optimize and synthesize nano-niosomes for the encapsulation of triacontanol. Niosomes were synthesized using a thin-film hydration method combined with ultrasonication, following a Box–Behnken design. Niosomes were characterized using various techniques including dynamic light scattering, Fourier-transform infrared spectroscopy (FTIR), confocal microscopy, high-resolution scanning electron microscopy, and transmission electron microscopy (TEM). Formulation 14 of niosomes achieved the desired size, polydispersity index (0.198 ± 0.008), and zeta potential (−31.28 ± 1.21). FTIR analysis revealed a characteristic signal in the 3400–300 cm−1 range, indicating intermolecular interactions due to a bifurcated hydrogen bond between cholesterol and S60. Confocal microscopy confirmed the presence of triacontanol through Nile Red fluorescence. TEM revealed the spherical structure of niosomes. [ABSTRACT FROM AUTHOR]

Here we report on light-triggered generation of local flow utilizing a bio-compatible non-ionic photo-active surfactant. The mechanism is based on diffusioosmotic phenomenon, where the gradient of relative concentration with respect to different chemical species near a surface leads to an osmotic pressure gradient driving liquid flow along the surface. The application of a photo-responsive surfactant allows for easy and reversible changes in concentration gradient by positioning a light source at the desired place. Along with the so-inscribed concentration gradient one can change reversible the direction and strength of the flow even in a closed system. The phenomenology of light-driven diffusioosmotic flow (LDDO) can be used in a rather flexible way: colloids can be gathered or dispersed and bio-compatibility extends the range of colloid types also to living microorganisms such as soil bacterium Pseudomonas putida. We show that DO flow can be considered a versatile method to set hydrodynamic conditions along the sample for investigating the motility of living cells. Further advantages of employing LDDO are the flexibility of flow generation in a reversible way and with spatiotemporal control, without the need to either change the channel geometry by loading a different device, or the periphery of pumps and connectors. [ABSTRACT FROM AUTHOR]

Bicarbonate and CO2 are essential substrates for carboxylation reactions in bacterial central metabolism. In Staphylococcus aureus, the bicarbonate transporter, MpsABC (membrane potential-generating system) is the only carbon concentrating system. An mpsABC deletion mutant can hardly grow in ambient air. In this study, we investigated the changes that occur in S. aureus when it suffers from CO2/bicarbonate deficiency. Electron microscopy revealed that ΔmpsABC has a twofold thicker cell wall thickness compared to the parent strain. The mutant was also substantially inert to cell lysis induced by lysostaphin and the non-ionic surfactant Triton X-100. Mass spectrometry analysis of muropeptides revealed the incorporation of alanine into the pentaglycine interpeptide bridge, which explains the mutant's lysostaphin resistance. Flow cytometry analysis of wall teichoic acid (WTA) glycosylation patterns revealed a significantly lower α-glycosylated and higher ß-glycosylated WTA, explaining the mutant's increased resistance towards Triton X-100. Comparative transcriptome analysis showed altered gene expression profiles. Autolysin-encoding genes such as sceD, a lytic transglycosylase encoding gene, were upregulated, like in vancomycin-intermediate S. aureus mutants (VISA). Genes related to cell wall-anchored proteins, secreted proteins, transporters, and toxins were downregulated. Overall, we demonstrate that bicarbonate deficiency is a stress response that causes changes in cell wall composition and global gene expression resulting in increased resilience to cell wall lytic enzymes and detergents. [ABSTRACT FROM AUTHOR]

The influence of adding surfactants on the performance of high-solid anaerobic digestion of horticultural waste was extensively investigated in batch systems. Adding Tween series and polyethylene glycol series non-ionic surfactants had positive effects on biogas production, resulting in 370.1 mL/g VS and 256.6 mL/g VS with Tween 60 and polyethylene glycol 300 at a surfactant-to-grass mass ratio of 0.20, while the biogas production of anaerobic digestion without surfactants was 107.54 mL/g VS. The optimal and economically feasible choice was adding Tween 20 at a ratio of 0.08 g/g grass in high-solid anaerobic digestion. A kinetics model reliably represented the relationship between surfactant concentration and biogas production. The mechanism of surfactants working on lignocellulose was investigated. The improvement in high-solid anaerobic digestion by adding surfactants was attributed to the interaction between lignocelluloses and surfactants and the extraction of biodegradable fractions from the porous structure. An economic analysis showed that adding Tween 20 was likely to make a profit and be more feasible than adding Tween 60 and polyethylene glycol 300. This study confirms the enhancement in biogas production from horticultural waste by adding non-ionic surfactants. [ABSTRACT FROM AUTHOR]

To solve the bottleneck of low degradation rate and low biogas yield in anaerobic digestion of food waste, the addition of anionic surfactant sodium N-lauroylsarcosinate (SN) and nonionic surfactant primary alcohol ethoxylate (AEO) were proposed. The results showed that both surfactants could promote the methane production and facilitate the degradation of food waste. The highest methane yield per mass of volatile solid was obtained in 0.1 g/L AEO (497.14 mL) and 1 g/L SN (445.51 mL), which was improved by 92% and 72% compared with the control group. While with the increase of surfactant concentration, methane yield was decreased due to negative effect caused by the surfactant. This corresponded with the variation of pH, total volatile fatty acids (TVFAs), and soluble chemical oxygen demand (SCOD). The microbial community analysis showed that the relative abundance of methanobacterium increased while the relative abundance of methanosaeta decreased after the addition of surfactant. Meanwhile, the methane production pathway was shifted from codominance of hydrogenotrophic and aceticlastic methanogens to predominance by hydrogenotrophic methanogens in the groups with low concentration of AEO and SN. [ABSTRACT FROM AUTHOR]

Nano SiO2 particles (NPs) combined with organosilane surfactants present a promising avenue for the development of stable fluorine-free firefighting foams. In this study, hydrophilic nano SiO2 particles, non-ionic organosilane surfactant (SiCare2238), and amphoteric hydrocarbon surfactant (LAMC) were prepared as a mixed dispersion to investigate the interactions between nano particles and surfactants, foaming ability, and foam stability of the mixed dispersion. Results indicated that the surface activity, electrical conductivity, and foaming ability of the mixed dispersion decreased with increasing NPs concentration. The impact of NPs on foam stability depended on the filling and blocking mechanisms within the platform boundary of the formed liquid film. At NPs concentrations below 1.5%, strong electrostatic interactions among surfactant molecules resulted in the adsorption of surfactant molecules on the nano particle surface, preventing the formation of a network structure at the platform boundary, thereby reducing foam stability. At NPs concentrations above 1.5%, a significant number of NPs formed a network structure, filling and blocking the platform boundary, leading to delayed foam drainage, coarsening, and enhanced foam stability. This study provides theoretical guidance for the application of nano particles in fluorine-free. [ABSTRACT FROM AUTHOR]

Sucrose esters have been deployed as surfactants in many food products since the 1950s. In addition to their useful physical characteristics, sucrose esters also have interesting biological properties that enhance their utility. This review critically examines the broad suite of biological activities that has been attributed to both synthetically-derived and naturally-occurring sucrose esters. These include insecticidal, molluscicidal, plant growth-regulating, anti-microbial, anti-tumor, anti-oxidant, anti-depressive, neuro-protective, anti-inflammatory and anti-plasmodial effects. In addition to providing a summary of the structure-activity profiles of sucrose esters, the various known mechanisms-of action of these compounds are also discussed. Furthermore, since sucrose esters are well-known surfactants, the potential to advantageously apply their industrially desirable physical characteristics in combination with their biological properties is considered. Recent advances in synthetic chemistry that have facilitated the deployment of biologically active sucrose esters as food additives are also described. [ABSTRACT FROM AUTHOR]

[Display omitted] The formation of adducts via urea interaction with distinct classes of surfactants (cationic, anionic, nonionic, and zwitterionic), leading to their assembly into lamellar structures and subsequent formation of hydrogels. The characteristics of these hydrogels are associated with both, the length of the alkyl chain, and the specific head group of the surfactant molecules. Characterization of adduct formation was conducted using Wide-Angle X-ray Scattering (WAXS), while Small-Angle X-ray Scattering (SAXS) was employed to probe the subsequent assembly into lamellar structures. The kinetics of hydrogel formation were assessed through rheological measurements and observed thermal transitions utilizing Differential Scanning Calorimetry (DSC). The investigation revealed a universal propensity for hydrogel formation across all surfactant classes. The formation arises from the interactions between urea molecules via hydrogen bonding, forming adducts around the surfactant chains. In sequence, the adducts self-assemble in lamellae. This process constructs the intricate three-dimensional network characteristic of the hydrogel. Furthermore, the kinetics of hydrogel formation, and their rheological properties under equilibrated conditions, were found to be significantly influenced by the nature of the polar head group of the surfactant molecules. This is the first evidence on the formation of adducts of urea with classes of surfactants. As they are common components in cosmetic, supramolecular hydrogels have high potential to be used in formulations. [ABSTRACT FROM AUTHOR]

Selecting the appropriate surfactant as a foaming agent is crucial in the production of foamed concrete. In this study, multiple technological approaches were employed for the investigation of the effect of three different types of surfactants as foaming agents; the approaches included surface tension measurement, zeta potential analysis, spectrophotometry, and nanoindentation. The results showed that the surface activity, solution viscosity, and environmental pH all influenced the generation and stability of foam in foaming agents. The adsorption process of surfactants onto cement particles was complex and could be effectively explained using the double-layer theory. The adsorption of anionic surfactant molecules on cement particles significantly altered the zeta potential, up to −17 mV, with an adsorption efficiency over 10 times greater than that of cationic surfactants and more than 5 times greater than that of nonionic surfactants. Furthermore, after cement hardening, the mechanical properties of the resulting pores were notably improved due to the presence of adsorbed anionic surfactants, and the maximum compressive strength could exceed 10 MPa. [ABSTRACT FROM AUTHOR]

Cloud point extraction (CPE) has emerged as a highly promising method for the isolation and preconcentration of trace elements from beverages. By utilizing nonionic surfactants to form micellar structures that encapsulate analytes, CPE significantly enhances extraction efficiency and detection limits, often achieving improvements by several orders of magnitude. The optimization of CPE conditions, particularly the selection of surfactants and complexing agents, plays a crucial role in ensuring accurate analytical results. This review underscores the integration of CPE with spectrometric methods as a powerful approach for the separation, preconcentration, and quantification of numerous (ultra)trace elements across a wide range of beverages, including drinking water, wine, beer, juices, tea, and milk. The analytical potential of this integration is substantiated by the comprehensive examples listed in this paper, which include various strategies for sample preparation tailored specifically for different beverage types. While highlighting the effectiveness of conventional CPE methods, this review also emphasizes recent modifications and advancements in CPE techniques that further enhance their utility in beverage analysis. These advancements not only improve detection sensitivity but also align with the principles of green chemistry by reducing solvent consumption and energy requirements. [ABSTRACT FROM AUTHOR]

Solid silicon (Si) microneedles have many applications such as skin pretreatment to form micrometer-sized holes in the skin surface in transdermal drug delivery systems. Wet etching based on tetramethylammonium hydroxide (TMAH) is an efficient method to fabricate solid microneedles. However, it is challenging to increase the density of microneedle arrays due to the faster lateral etching than the vertical etching that requires a large initial mask size. In this work, we used wet etching based on TMAH to fabricate solid Si microneedles. One kind of nonionic surfactant, Triton X-100, was introduced into the TMAH solution to suppress the lateral etching. When Triton X-100 was added into TMAH for a given etching condition, the maximum height (attained right before the mask fell off) of microneedles could reach ∼230 μm for 600 μm square-shaped mask size and 700 μm array period, compared to microneedles of maximum 152 μm height for the same mask size and period without surfactant addition. Correspondingly, when the target heights of microneedles were the same as ∼230 μm, denser (down to 700 μm period, 600 μm mask size) microneedle arrays were achieved with the help of Triton X-100, in comparison to arrays down to 900 μm period (800 μm mask size) without surfactant addition. Furthermore, agitation by a magnetic stirring bar is important for the fabrication of dense solid Si microneedle arrays based on TMAH. The microneedle structures were rhombic pyramid in shape with Triton X-100 and agitation. But microneedle structures obtained with Triton X-100 yet without agitation were octagonal pyramid in shape with a much less steep side surface. [ABSTRACT FROM AUTHOR]

[Display omitted] Nonionic surfactant aerosols play a crucial role in many industries, but they can cause acute irritation to users' eyes during spraying. This cytotoxic process is associated with corneal cell necrosis causing cell membrane disruption. Industrial grade surfactants are typically polydisperse mixtures described by their nominal chemical structure but how the polydispersity affects their interactions with cell membrane, remains largely unexplored. A better understanding could benefit product formulations to maximise their efficiency whilst minimising their toxicity to the users. In this study, poly - oxyethylene glycol monododecyl ethers (C 12 E 4 , C 12 E 23) were used to form ideal binary surfactant mixtures. The cytotoxicities of mono and polydispersed surfactants towards human corneal epithelial cells were examined, followed by a series of biophysical characterisations of interactions between surfactants and model cell membranes. Notably, to probe the journey of individual C 12 E 4 and C 12 E 23 surfactant molecules across the cell membrane from a binary surfactant mixture, "two-colour" neutron reflection measurements were achieved via Hydrogen/Deuterium substitution. The relative distributions of C 12 E 4 and C 12 E 23 across cell membranes and their nanostructural conformations revealed a synergistic membrane-lytic ability initiated by surfactant mixing, with the more hydrophobic C 12 E 4 exhibiting stronger membrane binding potency than the hydrophilic C 12 E 23. The exact molar ratio of C 12 E 4 against C 12 E 23 in the mixture determined how the mixed surfactant interacted with the cell membrane, and how the process directly impacted cytotoxicity and eye irritation. Thus, the cytotoxicity of polydisperse surfactants is not the same as monodisperse surfactant of the same average structure. This work provides a useful basis for the assessment of surfactant mixing by balancing their efficiency and toxicity. [ABSTRACT FROM AUTHOR]

[Display omitted] Seeking effective ways to maintain cellular homeostasis is crucial to the survival of organisms when they encounter osmotic stress. Glycine betaine (GB) is a widely generated natural osmolyte, but its endogenous production and action are limited. Herein, a kind of nonionic surfactant dodecyl-β-d-glucopyranoside (DG) and a common polymer polyethylene glycol (PEG) are proven to have the ability to enhance the osmotic stress (induced by sugar concentration changes) tolerance of cell and organism models, those are giant unilamellar vesicles (GUVs) and gram-negative Escherichia coli. DG or PEG only induces small size decrease and certain shape change of GUVs. Importantly, DG or PEG at the concentration 100 times lower than that of GB effectively increases the survival rate of bacteria under both hypoosmotic and hyperosmotic conditions. This intriguing result is attributed to the insertion of DG or adsorption of PEG in the lipid bilayer membrane, leading to enhanced membrane permeability. These exogenous substances can replace GB to facilely and highly efficiently augment adaptation of organisms to osmotic stress. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tween 80 additive modifies the solvation structure of Zn2+ ions. • Tween 80 additive reconstructs the hydrogen bond network in ZnSO 4 electrolyte. • Zn2+ ions complexed with Tween-80 create a protective hydrophobic layer. • Dual-layer Tween-80 on Zn anode prevents corrosion, reduces hydrogen evolution. Zinc metal anodes encounter significant challenges, including dendrite growth, hydrogen evolution, and corrosion, all of which impede the rate capability and longevity of aqueous zinc-ion batteries (AZIBs). To effectively tackle these issues, we introduced Tween-80 into the traditional ZnSO 4 electrolyte as an additive. Tween-80 possesses electronegative oxygen atoms that enable it to adsorb onto the zinc (Zn) anode surface, facilitating the directional deposition of Zn metal along the (0 0 2) orientation. The hydroxyl and ether groups within Tween-80 can displace some of the coordinated water molecules in the Zn2+ inner solvation shell. This disruption of the hydrogen bond network regulates the solvation structure of Zn2+ ions and suppresses the possibility of hydrogen evolution. Moreover, the long hydrocarbon chain present in Tween-80 exhibits excellent hydrophobic properties, aiding in the resistance against corrosion of the Zn anode by water molecules and reducing hydrogen evolution. Consequently, a symmetric cell equipped with the Tween-80 additive can cycle stably for over 4000 h at 1 mA cm−2 and 1 mA h cm−2. When paired with the V 2 O 5 cathode, the full cell demonstrates a high-capacity retention rate exceeding 80 % over 1000 cycles at a current density of 2 A g−1. This study underscores the advantages of utilizing non-ionic surfactants for achieving high-performance aqueous zinc-ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] In order to understand the basic mechanisms affecting emulsion stability, the intrinsic dynamics of the drop population must be investigated. We hypothesize that transient ballistic motion can serve as a marker of interactions between drops. In 1G conditions, buoyancy-induced drop motion obscures these interactions. The microgravity condition onboard the International Space Station enable this investigation. We performed Diffusing Wave Spectroscopy (DWS) experiments in the ESA Soft Matter Dynamics (SMD) facility. We used Monte Carlo simulations of photon trajectory to support data analysis. The analysis framework was validated by ground-based characterizations of the initial drop size distribution (DSD) and the properties of the oil/water interface in the presence of surfactant. We characterized the drop size distribution and found to be bi-disperse. Drop dynamics shows transient ballistic features at early times, reaching a stationary regime of primarily diffusion-dominated motion. This suggests different ageing mechanisms: immediately after emulsification, the main mechanism is coalescence or aggregation between small drops. However at later times, ageing proceeds via coalescence or aggregation of small with large drops in some emulsions. Our results elucidate new processes relevant to emulsion stability with potential impact on industrial processes on Earth, as well as enabling technologies for space exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] Hypothesis: Limited research has been conducted on the influence of chelating agents on the self-assembly process in surfactant solutions. The traditional approach assumes the chelating agent only interferes as a salting-out ion, therefore promoting surfactant separation. However, the opposite behavior has been observed for iminodipropionate based surfactants, in which the presence of chelating agents of the aminopolycarboxylate type increases solubility of nonionic ethoxylated surfactants in mixed micellar systems. Specific interaction between chelating agents-surfactants can be an important parameter in the self-assembly processes. Experiments: Physicochemical properties of solutions containing amphoteric surfactant and tetrasodium glutamatediacetate have been investigated. Macroscopic properties, such as viscosity and cloud point, were evaluated in the presence of a non-water-soluble alkyl ethoxylated surfactant. Interactions between amphoteric surfactant and chelating agent were monitored by NMR spectroscopy, including 13C chemical shift and lineshape analysis as well as 1H diffusometry. Findings: The study reveals that there is an interaction between the head group of the surfactant and the chelating agent forming oligomeric surfactant analogues with larger hydrophilic moieties, which results in smaller, more spherical micelles. The combined interactions provide possibilities for tuning the aggregation behavior of systems containing surfactants and chelating agents, and with that, the macroscopic properties of the system. [ABSTRACT FROM AUTHOR]

[Display omitted] Ethoxylated nonionic surfactants are promising candidates for enhanced oil recovery (EOR) from oil-wet carbonate reservoirs due to their ability to reverse the mineral wettability. The wettability-reversal efficiency increases with the number of the ethoxy (EO) groups in the surfactant molecule. Contact angle measurements, scanning electron microscopy (SEM) and molecular dynamics (MD) simulations were combined to investigate the wettability reversal of an oil-wet calcite by three ethoxylated nonionic surfactants with 1, 4 and 8 EO groups, respectively, to directly probe the role of the EO groups and to uncover the molecular mechanism responsible for the wettability reversal. Both experiments and simulations consistently show a clear correlation between the number of EO groups and the wettability reversal efficiency of the surfactants, whereby the higher number of EO groups results in greater degree of wettability reversal. This is due to 1) the more hydrophilic surfactant headgroup weakening the carboxylate interactions with the surface by expanding the surface-adjacent water layer, and 2) the physically larger surfactant molecule attracting the carboxylates more strongly, thus aiding in their removal from the surface. [ABSTRACT FROM AUTHOR]

Heterogeneous combination flooding systems are composed of surfactant and viscoelastic preformed gel particles (PGP) that can migrate in the pores. The interactions between PGP and surfactants have an important impact on the system. In our research described here heterogeneous aqueous suspensions of PGP and an anionic surfactant (sodium dodecyl benzene sulfonate, SDBS) or a nonionic surfactant coconut oil alkanolamide, (CDEA) were prepared. The effects of SDBS and CDEA on the swelling and rheological properties of the PGP was investigated. In addition, the influence of SDBS and CDEA on the thermal effects of PGP was studied. The results showed that the swelling ratio, apparent viscosity and storage modulus of the PGP decreased with the increase of SDBS concentration. On the contrary, the CDEA increased the swelling ratio and the rheological properties of PGP. The specific heat capacity ( C p ) of PGP increased with the SDBS concentration and decreased with the CDEA concentration. Similar to the rheological behavior, the influence of interactions on the PGP molecular thermal motion was related to the concentration of the surfactants. Therefore, studying the variation of C p with concentration can provide reference for the reasonable dosage of surfactants in heterogeneous oil displacement systems and a new perspective for investigating the interaction between surfactant and PGP or other polymers. [ABSTRACT FROM AUTHOR]

Coarse grained simulations were adopted to describe the encapsulation and dispersion of fullerene C$_{60}$ 60 by hexaoxyethylene dodecyl ether (C$_{12}$ 12E$_6$ 6) surfactants. The self-organised structures of C$_{12}$ 12E$_6$ 6 molecules in water were captured and the characteristics of micelles composed of different number of C$_{12}$ 12E$_6$ 6 molecules were analysed. We found that C$_{60}$ 60 molecules alone or in clusters can spontaneously translate into the hydrophobic core of micelles. One monomeric C$_{60}$ 60 can explore the hydrocarbon-chain region of the micelles with different sizes, and two different preferential locations of C$_{60}$ 60 are observed. The small C$_{60}$ 60 clusters can disaggregate after entering the micelle. Larger C$_{60}$ 60 clusters can penetrate into the micelle as solid-like nanoparticles, although they are partially disaggregated. When investigating the self-assembly of C$_{12}$ 12E$_6$ 6 surfactants and C$_{60}$ 60 molecules, we found that it is very difficult to disperse C$_{60}$ 60 in the micelle monomolecularly. At high molar ratio of C$_{12}$ 12E$_6$ 6/C$_{60}$ 60, colloidal nanoC$_{60}$ 60 aggregates form with C$_{12}$ 12E$_6$ 6 surfactants adsorbed on the surface. Our simulations provide an explanation for the different observations in fullerene solubilization in micellar solutions and give a guideline for further solubilization of pristine fullerene or small hydrophobic molecules with surfacant micelles, which is helpful for the design of new micelle-based delivery vehicles. [ABSTRACT FROM AUTHOR]

The reported work is focused on the solubility of Rhodamine B (cationic dye), as an important methodology to investigate the extent of incorporation or penetration of dye inside the micelles spectroscopically, so the solubilised dye can be filtered via Micellar-enhanced ultrafiltration process to keep our environment safe from toxic effects of industrial effluent. Solutions were prepared by using micellar media of anionic surfactants i.e. Sodium dodecyl sulphate (SDS), Sodium Oleate (SO) as well as mixed micellar media of said anionics with non-ionic surfactant i.e. Triton X-100 (TX-100). The extent of solubilisation has been, quantitatively, calculated using data of differential spectroscopy, in terms of partition coefficient Kx and Gibbs energy of partition, ∆Gp. It has been observed that mixed micellar media has better solubilisation capacity than micellar solution of individual surfactants. A better micellar solubilisation and ultimately the high Gibbs energy of partition, ∆Gp with SO/TX-100 system i.e. −40.89 as compared to SDS/TX-100 system (−37.03) has been observed due to the presence of long carbon chain in SO. [ABSTRACT FROM AUTHOR]

In high‐temperature and high‐salt environments, emulsions stabilized by surfactants are susceptible to instability phenomena, such as droplet coalescence, thereby limiting their utility in tertiary oil recovery. The Pickering emulsions, which are stabilized by solid particles, have been proved to exhibit good stability. This study demonstrated that the nonionic surfactant C16E20 can adsorb onto SiO2 nanoparticles with an efficiency exceeding 99%, rendering C16E20 suitable for modulating the wettability of SiO2 nanoparticles. By adjusting the proper surfactant‐to‐nanoparticle ratio, such as 0.1%:1.0%, a hydrophilic–lipophilic equilibrium is obtained, which is beneficial for the preparation of Pickering emulsions. Laser confocal and cryo‐scanning electron microscopy results indicated that SiO2 nanoparticles in Pickering emulsions were dispersed at the oil–water interface, forming a network structure between the emulsion droplets. Further experiments illustrated that the Pickering emulsions showed excellent stability for at least 180 days at 80°C. Conventional emulsions behave as Newtonian fluids at lower oil‐phase ratios, while Pickering emulsions exhibit non‐Newtonian fluid properties, with their viscosity capable of increasing by over 100 times. Additionally, Pickering emulsions were found to exhibit thixotropy, attributed to the reversible formation and destruction of droplet bridging structures. Overall, Pickering emulsions are regarded as potential agents for Enhanced Oil Recovery in oilfield development. [ABSTRACT FROM AUTHOR]

Rechargeable aluminum batteries (RABs) have garnered attention owing to their impressive theoretical capacity, outstanding safety features, and abundant Al reserves, thereby positioning them as a potential alternative and supplement to fixed energy storage. Nonetheless, RABs still suffer from issues, such as poor anode stability stemming from the corrosivity of the chloral aluminate ionic liquid electrolyte (ILs) and subpar wettability of the cathode. To address these issues, the proposed electrolyte interfacial engineering involves the nonionic surfactant (F127) as an interfacial optimizer in ILs, simultaneously modulating the anode–electrolyte and cathode–electrolyte interfaces. Systematic experiments and theoretical analyses validate that F127 preferentially adsorbs on the electrode surface, forming a dense and uniform adsorption layer. The F127 layer can effectively mitigate the corrosion of ILs on the Al anode and regulate the current density to achieve uniform Al deposition. Furthermore, F127 enhances the wettability between the cathode and ILs, preventing the collapse of the graphite structure and enhancing the active material's utilization. The Al//FG full battery assembled with F127 modifying ILs (F127‐0.5) is able to retain a specific capacity of 104.9 mAh g−1 after 1600 cycles, which is higher than ILs (69.0 mAh g−1). This electrolyte interface modification strategy holds considerable practical significance for achieving long‐lifespan and high‐capacity RABs. [ABSTRACT FROM AUTHOR]

Dynamic light scattering has been employed to investigate aqueous Pluronic P123 solutions at different temperatures and in the presence of different solvents and quercetin additives. Significant changes have been revealed in the average particle size and polydispersity index depending on the conditions. The effect of temperature on micellization of the block copolymer in aqueous solutions has been studied in a range T = 15–45°C, which is most often considered when using P123 in the sol–gel synthesis of silica. The most pronounced effect of temperature on the micellization of the studied surfactant has been observed at T = 15–20°C. In this temperature range, the scattered light intensity distribution over particle sizes has a polymodal character, which indicates the presence of macromolecules, micelles, and their aggregates in the system. A further increase in temperature up to 45°C causes no significant changes in the particle size. In aqueous solutions, micelles with a narrow size distribution (minimum polydispersity index) are formed within temperature ranges of 21–25 and 35–40°C. Substantial effects have been found when adding alkanols and polyphenolic substances as solubilizers capable of influencing the structure of micelles both in their bulk and on the surface of polar moieties of the surfactant. It has been shown that, in the presence of butanol-1, micelles are stabilized at temperatures of 15–20°C. At T > 30°C, the structure of micelles is transformed. As the fraction of butanol-1 in the solution increases, its influence is manifested at lower temperatures. It has been noted that ethanol has a destructive effect on micelles. Additives of quercetin exhibit an opposite effect of micelle stabilization, which leads to the formation of a homogeneous surfactant structure. It has been shown that, by varying solvent composition, the flavonoid–micelle binding can be controlled due to changes in the solvation. The greatest influence of quercetin on the structure formation of P123 has been observed at a solvent composition corresponding to ethanol-to-block copolymer molar ratio of n(EtOH) : n(P123) = 80 : 1. [ABSTRACT FROM AUTHOR]

A spectrophotometric method has been employed to study micellization of nonionic surfactants (NSs), namely, polyoxyethylated alkylphenols, Triton X-100 (TX-100) and Triton X-114 (TX-114), in aqueous solutions. The spectral characteristics have been calculated for the curves of light absorption by surfactant solutions in concentration ranges of 0.02–0.80 and 0.02–0.40 mmol/L for TX-100 and TX-114, respectively. The influence of the steps of scanning along the wavelength scale (0.1, 0.2, 0.5, and 1.0 nm) on the positions of the maxima and the intensities of the absorption has been studied. The optical density has been found to increase monotonically throughout the concentration range. It has been revealed that, at all scanning steps, a bathochromic shift is observed for the absorption maximum of the long-wavelength band (275 nm) by 1.5 and 2.0 nm for TX-114 and TX-100, respectively, at certain NS concentrations. The curve for the dependence of absorption maximum position on NS concentration exhibits a characteristic inflection, whose position depends on the scanning step. A new method has been proposed for the spectrophotometric determination of the critical micelle concentrations (CMCs) of TX-100 and TX-114 from the dependence of the position of the absorption maximum of the long-wavelength band in the electronic absorption spectrum on the surfactant concentration in an aqueous solution. It has been found that a scanning step of 0.1 nm is optimal for the graphical determination of CMC. The CMC values have been determined for TX-100 and TX-114. The obtained values have appeared to be consistent with the literature data and equal to (0.24 ± 0.02) and (0.20 ± 0.01) mmol/L, respectively. [ABSTRACT FROM AUTHOR]

Protein denaturation and aggregation resulting from the effects of interfacial stress, often enhanced by flow and shear stress, pose significant challenges in the production of therapeutic proteins and monoclonal antibodies. The influence of flow on protein stability is closely intertwined with interfacial effects. In this study, we have developed a microfluidic device capable of exposing low volume (< 320 µL) protein solutions to highly uniform shear. To disentangle the synergistic impact of flow and interfaces on protein aggregation, we fabricated two devices composed of different materials, namely poly(methyl methacrylate) (PMMA) and stainless steel. Upon application of shear, we observed formation of protein particles in the micron-size range. Notably, The number of particles generated in the steel devices was ∼ 3.5 fold lower than in the PMMA device, hinting at an interface-mediated effect. With increasing the protein concentration from 1 to 50 mg/mL we observed a saturation in the amount of aggregates, further confirming the key role of solid-liquid interfaces in inducing particle formation. Introduction of non-ionic surfactants prevented protein aggregation, even at the highest tested protein concentration and low surfactant concentrations of 0.05 mg/mL. Overall, our findings corroborate the synergistic impact of shear and interface effects on protein aggregation. The device developed in this study offers a small-scale platform for assessing the stability of antibody formulations throughout various stages of the development and manufacturing process. [ABSTRACT FROM AUTHOR]

Microwave-assisted de-emulsification is attractive in the processes of petroleum production and refining. The main advantage of microwaves is their direct influence on the surfactant layer at the oil/water interface. Previously, an effective interfacial modification was demonstrated by pulsed microwave irradiation. However, the effect of the modification diminished during the off interval of the pulse irradiation. In this study, two-stage microwave irradiation with different powers and durations was applied as a method to maintain an interfacial effect. The power of the second stage was changed to optimise the modification. Quick modification was obtained by high-power irradiation followed by low-power irradiation. It was confirmed a sustained modification was maintained by a moderate power of the second irradiation. This observation indicates a re-adsorption or re-structure process after the first irradiation is suppressed by the second irradiation. The results open new opportunities to optimise microwave operation in oil/water systems. [ABSTRACT FROM AUTHOR]

Salt-induced diffusiophoresis is the migration of a colloidal particle in water due to a directional salt concentration gradient. An important example of colloidal particles is represented by micelles, generated by surfactant self-assembly in water. For non-ionic surfactants containing polyethylene glycol (PEG) groups, PEG preferential hydration at the micelle–water interface is expected to drive micelle diffusiophoresis from high to low salt concentration. However, micelles are reversible supramolecular assemblies, with salts being able to promote a significant change in micelle size. This phenomenon complicates the description of diffusiophoresis. Specifically, it is not clear to what extent the salt-induced growth of micelles affects micelle diffusiophoresis. In this paper, a multiple-equilibrium model is developed for assessing the contribution of the micelle growth and preferential hydration mechanisms to the diffusiophoresis of non-ionic micelles. The available experimental data characterizing the effect of NaCl on Triton X-100 aggregation number are combined with data on diffusiophoresis and the preferential hydration of PEG chains to show that the contribution of the micelle growth mechanism to overall diffusiophoresis is small compared to that of preferential hydration. [ABSTRACT FROM AUTHOR]

Alcohol ethoxylates (AEs) are a well-known class of non-ionic surfactants widely used by the personal care market. The aim of this study was to evaluate and characterize the in vitro metabolism of AEs and identify metabolites. Five selected individual homologue AEs (C8EO4, C10EO5, C12EO4, C16EO8, and C18EO3) were incubated using human, rat, and hamster liver S9 fraction and cryopreserved hepatocytes. LC–MS was used to identify metabolites following the incubation of AEs by liver S9 and hepatocytes of all three species. All AEs were metabolized in these systems with a half-life ranging from 2 to 139 min. In general, incubation of AE with human liver S9 showed a shorter half-life compared to rat liver S9. While rat hepatocytes metabolized AEs faster than human hepatocytes. Both hydrophobic alkyl chain and hydrophilic EO head group groups of AEs were found to be target sites of metabolism. Metabolites were identified that show primary hydroxylation and dehydrogenation, followed by O-dealkylation (shortening of EO head groups) and glucuronidation. Additionally, the detection of whole EO groups indicates the cleavage of the ether bond between the alkyl chain and the EO groups as a minor metabolic pathway in the current testing system. Furthermore, no difference in metabolic patterns of each individual homologue AE investigated was observed, regardless of alkyl chain length or the number of EO groups. Moreover, there is an excellent agreement between the in vitro experimental data and the metabolite profile simulations using in silico approaches (OECD QSAR Toolbox). Altogether, these data indicate fast metabolism of all AEs with a qualitatively similar metabolic pathway with some quantitative differences observed in the metabolite profiles. These metabolic studies using different species can provide important reference values for further safety evaluation. [ABSTRACT FROM AUTHOR]

Surfactants are widely used in fields such as oil recovery and flotation. The properties and mechanisms of surfactants can be effectively studied using molecular dynamics (MD) simulations. Herein, the aggregation behavior of surfactants was studied at the oil–water interface by MD simulation, and the micro-morphology of surfactants was analyzed under a low concentration and saturated state at the oil–water interface, respectively. The visualization results of the MD simulation showed that DTOA was saturated at the oil–water interface at 120 surfactant molecules, whereas 160 surfactant molecules were required for BEMA. In addition, the effect of surfactant concentration on the interfacial thickness and hydrogen bond distribution was studied, with the inflection point of hydrogen bond distribution identified as a characteristic parameter for surfactant saturation at the oil–water interface. The aggregation behavior of their hydrophobic and hydrophilic chains at the oil–water interface was qualitatively assessed using order parameters. Finally, the aggregation state of surfactants in salt-containing systems was studied, and it was found that the surfactants could effectively adsorb magnesium ions and calcium ions at the oil–water interface. However, the curve of the number of hydrogen bonds varies greatly, with a possible reason being that BEMA has a different coordination manner with diverse metal ions. This study provides some original insights into both the theoretical study and practical application of anionic and nonionic surfactants. [ABSTRACT FROM AUTHOR]

Rationale: Various medium formulations contain essential fatty acids at concentrations ranging from 10 to 100 mg/L. Accurate and precise lipid measurement in media is crucial for monitoring media quality and conducting studies on lipids in the context of cell culture. This study employed two‐dimensional gas chromatography (GC × GC) analyses to offer enhanced resolution, sensitivity, and separation performance compared to GC. Methods: Quantification of fatty acid methyl esters (FAMEs) in a medium was conducted using GC × GC combined with a high‐resolution mass spectrometer and flame ionization detector, considering potential interference from nonionic surfactant Tween 80, which was precipitated and removed by optimizing the concentration of cobalt thiocyanate (CTA) solution during pretreatment. This advanced analytical approach enabled identification of cis and trans isomers of identical molecular weights and determination of the location and number of double bonds in the same carbon number structure. Results: Our analysis identified 36 FAMEs within the C6–C24 region, and a 5% CTA solution was optimal for efficient removal of Tween 80 during lipid extraction. Additionally, this advanced method minimized FAME contamination and loss during pretreatment, thereby significantly reducing the sample volume required to detect trace levels of FAMEs. This improvement led to a fatty acid recovery rate of 106% while maintaining the average relative standard deviation for the target FAMEs of about 3%. Conclusions: Our research paves the way for future investigation into medium quality control and the role of fatty acids in cell culture. This offers the possibility for economical and effective trace quantification of fatty acids in complex media. [ABSTRACT FROM AUTHOR]

Background: Commonly used media for the differentiation of human pluripotent stem cells into cardiomyocytes (hPSC-CMs) contain high concentrations of proteins, in particular albumin, which is prone to quality variations and presents a substantial cost factor, hampering the clinical translation of in vitro-generated cardiomyocytes for heart repair. To overcome these limitations, we have developed chemically defined, entirely protein-free media based on RPMI, supplemented with L-ascorbic acid 2-phosphate (AA-2P) and either the non-ionic surfactant Pluronic F-68 or a specific polyvinyl alcohol (PVA). Methods and Results: Both media compositions enable the efficient, directed differentiation of embryonic and induced hPSCs, matching the cell yields and cardiomyocyte purity ranging from 85 to 99% achieved with the widely used protein-based CDM3 medium. The protein-free differentiation approach was readily up-scaled to a 2000 mL process scale in a fully controlled stirred tank bioreactor in suspension culture, producing > 1.3 × 109 cardiomyocytes in a single process run. Transcriptome analysis, flow cytometry, electrophysiology, and contractile force measurements revealed that the mass-produced cardiomyocytes differentiated in protein-free medium exhibit the expected ventricular-like properties equivalent to the well-established characteristics of CDM3-control cells. Conclusions: This study promotes the robustness and upscaling of the cardiomyogenic differentiation process, substantially reduces media costs, and provides an important step toward the clinical translation of hPSC-CMs for heart regeneration. [ABSTRACT FROM AUTHOR]