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In water, the nonionic surfactant pentaethylene glycol monododecyl ether (C12E5) forms multi-lamellar vesicles upon application of shear, attributed to buckling instability of the surfactant layers. In the standard setup for applying shear, a pair of solid substrates is moved in opposite directions, and a non-slip condition at the solid surface is assumed. Based on theoretical predictions, the effective viscosity of the fluid surrounding the membrane is modified in this process, and this confinement may affect membrane fluctuation. However, only a few studies have analyzed the structural changes near the substrate. From this viewpoint, the structural changes in surfactant aggregates near a solid substrate under the application of shear were investigated herein using neutron reflectometry (NR). By increasing the shear rate, shear thickening at a lower shear rate and shear thinning at a higher shear rate were observed, similar to that in the bulk. However, a discontinuous change in the lamellar structure accompanying the condensation of the surfactant was observed in the NR experiments. This study presents the first experimental evidence indicating that the ramping speed of shear rates governs the shear-induced structuring of surfactant aggregates near the surface. [ABSTRACT FROM AUTHOR]

AbstractThe nonionic surfactant was considered to be the most effective surfactant for the treatment of oily sludge. In this paper, Tween20 and Span80 (T/S) composite surfactant was chosen as emulsifier for the preparation of microemulsion, and their synergistic effect was explored. Clint equation and molecular dynamics simulation was used to interpret the formation of mixed micelles and the results showed that T/S composite surfactant with the mass ratio of 11:1 exhibited the good synergetic effect. Then, the microemulsion prepared using composite surfactants was applied for the treatment of oily sludge. Under the optimal conditions of solid-liquid ratio of 1:1(g: mL), stirring temperature of 40 °C, stirring time of 30 min and stirring speed of 400 rpm, the residual oil rate was reduced to 0.25%, which was much lower than other reported results using chemical methods. Interface tensiometer and quartz crystal microbalance measurement showed that the interfacial tension decreased significantly after the addition of composite surfactant. This work provides a feasible strategy for oily sludge treatment using microemulsion, which promoted the development of oily sludge treatment processes based on microemulsion in practical industry. [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]

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]

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]

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]

[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]

[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]

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]

Investigating surfactant effects on the floatability of Wiser bituminous coal holds significant importance in improving coal cleanliness and utilization value. Using density functional theory and molecular dynamics simulation methods, this study constructed models of Wiser bituminous coal and examined the impact of different surfactants, including the anionic surfactant sodium dodecyl benzene sulfonate, the cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB), and the non-ionic surfactant fatty alcohol ethoxylated ether. The focus was on investigating the charge distribution characteristics of these molecules and the modifying effect of binary surfactants on the hydrophobicity of bituminous coal. Results revealed that the maximum electrostatic potential was concentrated near oxygen/nitrogen/sulfur-containing functional groups like sulfonic acid groups, quaternary ammonium cations, ethylene oxide, hydroxyl groups, carboxyl groups, and sulfur bonds. These functional groups exhibited a propensity for accepting/delivering electrons to form hydrogen bonds. Among the surfactants tested, CTAB revealed the slightest difference in frontier orbital energy, measuring 3.187 eV, thereby demonstrating a superior trapping ability compared with the other two surfactants. Adsorption reactions within the system were determined to be spontaneous, with over 60% of the interaction force attributed to electrostatic forces. Moreover, the repulsive force magnitude with water molecules followed the trend: sulfonate group (2.20 Å) < ethylene oxide (2.43 Å) < quaternary ammonium cation (2.57 Å), indicating more excellent water repellency of CTAB. Findings showed that CTAE binary surfactants proved most effective in modifying the hydrophobicity of bituminous coal. This study offers valuable insights into reducing waste, pollution, and resource wastage. [ABSTRACT FROM AUTHOR]

Hydrotropes are amphiphiles that improve the water solubility of hydrophobic substances. In this study, we systematically evaluated the effects of eight hydrotropes on the antibacterial activity of fatty acids solubilized in a micellar system. The antibacterial activity was evaluated using minimum inhibitory concentration (MIC) as an indicator, and CMC was calculated for interfacial properties based on the measurement of the surface tension and the solubilization behavior of the oil‐soluble dye. The solubilization of lauric acid (12:0 FA) in the micelles of nonionic surfactants increased and decreased the antibacterial activities of the surfactants against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis, respectively. The addition of the hydrotropes decreased the antibacterial activity of the surfactants against both Staphylococci. However, on introducing small amounts of 12:0 FA, the surfactants exhibited selective antibacterial activity against S. aureus. These antibacterial phenomena were observed at concentrations above the critical micelle concentration of the surfactants. These findings suggest that the addition of hydrotropes affects the interfacial properties and antibacterial activity of micellar systems containing antibacterial ingredients. [ABSTRACT FROM AUTHOR]

Foaming agents as a combination of several components are usually used as soil conditioning during earth pressure balance shield (EPBS) tunnelling. These residues in waste EPBS muck lead to a series of new challenges for in-situ recycling, i.e., foams overflow flocculation tank. This study investigates the effects of residual foaming agent components and defoamers on defoaming-flocculation-filterpress characteristics of EPBS muck using an improved flocculation and filterpress system. Residual foam height (Hf), defoaming ratio (DFR), antifoaming ratio (AFR), total suspended substance (TSS), turbidity, moisture content (MC), and zeta potential (ZP) were selected as characterization indices. The microstructure of filterpress cakes was analyzed using a scanning electron microscope. Results demonstrate that an enhancement within 0.0-1.0wt.% for sodium fatty alcohol polyoxyethylene ether sulfate (AES) and alpha olefin sulfonate (AOS) significantly reduces DFR and AFR. The MC and ZP decline, while the Hf and turbidity enhance. The combinations of nonionic surfactants alkyl polyglycoside (APG) and fatty alcohol-polyoxyethylene ether (AEO) in a concentration range of 0.0-1.0wt.% with 0.2wt.% AES causes the Hf, DFR, AFR, turbidity, and ZP to exhibit absolutely different variations. The MC with the growth in both APG and AEO presents a trend of first decreasing and then increasing. By increasing foam stabilizers sodium carboxymethyl cellulose (CMC) and guar gum (GG) within 0.02-0.10wt.%, the AFR, TSS, and ZP enhance in varying degrees, while the Hf, DFR, and MC gradually reduce. With the increase of defoamers hydroxyl silicone oil-glycerol polyoxypropylene ether (H-G) and dimethyl silicone oil-glycerol polyoxypropylene ether (D-G) within 0.002-0.010wt.%, the DFR and AFR are significantly improved, while the TSS, turbidity, MC, and ZP display varying degrees of reduction. Moreover, defoaming-flocculation-filterpress mechanisms of EPBS muck are explored to provide a useful reference for actual in-situ recycling projects. [ABSTRACT FROM AUTHOR]

The clay swelling is extremely harmful to the reservoir during tight oil and shale oil extraction. In order to prevent the interaction between clay and surfactants from making the clay to hurt reservoir during oil recovery, this paper studies the effects of different surfactants on reservoir clay. Clay-surfactant swelling experiments were conducted to observe the macroscopic effects of different surfactants on clay swelling and to summarize the rules, and molecular simulations were then used to explain this phenomenon. The results show that different surfactant groups have different tendencies to move toward the clay in water, with cationic groups moving toward the montmorillonite layers and anionic groups moving away from the montmorillonite layers, and nonionic does not have a significant effect. Cationic surfactant and amphoteric surfactant whose mechanism of inhibiting swelling action is directly reducing the negative electrical properties of the montmorillonite layers when Na+ outflow from montmorillonite layers, thus preventing electrostatic repulsion between montmorillonite layers to repel each other and move far away. In contrast, the nonionic surfactant, because it is not charged, cannot prevent the hydration of montmorillonite although there are surfactant molecules adsorbed on the layers due to van der Waals force; and the addition of anionic surfactant cannot suppress the negative electrical properties between the layers, which makes the diffusion of sodium ions between the layers augmented and promotes the swelling and dispersion of montmorillonite. This study is expected to provide benefits to oil production area by reducing the damage of surfactant imbibition fluid. [ABSTRACT FROM AUTHOR]

CO2 foam fracturing in tight and shale reservoirs is a revolutionary technique for commercially viable production. Nevertheless, the screening of foaming agents used in CO2 foam fracturing fluid and the understanding of foaming mechanisms have not been sufficiently investigated. This study aimed to provide a comprehensive method for evaluating and selecting an optimized foaming agent for CO2 foam fracturing fluid integrating macroscopic and microscopic approaches through laboratory experiments and molecular dynamics simulations. The relationship between the molecular structure of the foaming agent and its corresponding foaming effect was elucidated by taking the interaction between CO2 and the foaming agent into account. Foam evaluation experiments indicated that the anionic surfactants exhibited superior foaming capacity and inferior stability compared to zwitterionic and non-ionic surfactants. The molecular dynamics simulation results demonstrated that the foaming mechanism of the CO2 foaming agent relied on the equilibriums between CO2-surfactant, CO2-water, and surfactant–water interactions. At the same time, it was found that if the molecular structure of the surfactant contained functional groups that could produce hydrogen bonding with CO2, the stability of the foaming effect improved to a certain extent, but the foaming volume was not obvious. The classic hydrophilic–lipophilic balance (HLB) theory was not applicable when screening the CO2 foaming agents. It was found that the ionic surfactants with CO2-philic groups and linear structures were suitable as the main foaming agents for CO2 foam fracturing fluids, while non-ionic surfactants with significant steric hindrance were suitable as auxiliary foaming agents. This study provides valuable guidance for selecting cost-effective foaming agents on-site and adds to the understanding of the relationship between the molecular structure of foaming agents and their foaming effects. [ABSTRACT FROM AUTHOR]

Line tension in wetting processes is of high scientific and technological relevance, but its understanding remains vague, mainly because it is difficult to determine. A widely used method to extract line tension relies on the variation of a droplet's contact angle with the droplet's size. Such an approach yields the apparent line tension, which is an effective parameter that factors in numerous contributions to the finite-size dependence, thus masking the actual line tension in terms of the excess free energy of the three-phase contact line. Based on our recent computer simulation study, we investigate how small amounts of nonionic surfactants, such as surface-active impurities, contribute to the apparent line tension in aqueous droplets. When depositing polydisperse droplets, their different surface area-to-volume ratios can result in different final bulk concentrations of surfactants, different excess adsorptions to the interfaces, and, consequently, different contact angles. We show that already trace amounts of longer-chained surfactants in a pre-contaminated liquid are enough to affect measurements of the apparent line tension. Our analysis quantifies to what extent "background" impurities, inevitably present in all kinds of experimental settings, limit the resolution of line tension measurements, which is crucial for avoiding data misinterpretation. [ABSTRACT FROM AUTHOR]

The present work attempts to systematically explore the surfactant sorption at liquid–liquid interfaces with coarse-grained models targeting thermodynamic properties of reference liquid solutions. We employ dissipative particle dynamics with soft-core forcefield tested against experimental data on micellization of surfactants in water, and the previous results are reproduced in this work. We consider three different nonionic surfactants: hexaethylene glycol monododecyl ether (C12E6), 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol) known as Triton X-100 (TX-100), and two alkyl glucoside surfactants (CnG1) with n-alkane tail fragments and a saccharide hydrophilic head at decane–water and toluene–water interfaces. For TX-100, we composed a model based on the literature forcefield and found good agreement with the experimental critical micelle concentrations (CMCs). The head–head interactions are of different origins for different surfactant groups: entropic repulsion between ethylene oxide chains of C12E6 and TX-100, and more chemically specific and complex interactions between the maltose heads of alkyl glucosides. We interpret our results with the Redlich–Peterson equation of monolayer adsorption in order to relate the adsorption to the bulk concentration of the surfactant and the interfacial tension. The densities of the adsorbed monolayer at CMC mostly agree with the experimental data, and a reasonable agreement was obtained for the interfacial tension at CMC. At the same time, we found significant discrepancies between the simulated and experimental adsorption isotherms. We explain them by the oversimplified forcefield: when the parameters are fitted to the free energies of bulk solutions, they may not correctly reproduce the interfacial free energies. [ABSTRACT FROM AUTHOR]

Porous β-tricalcium phosphate (Ca3(PO4)2; β-TCP) was prepared via freeze-drying and the effects of this process on pore shapes and sizes were investigated. Various samples were prepared by freezing β-TCP slurries above a liquid nitrogen surface at −180 °C with subsequent immersion in liquid nitrogen at −196 °C. These materials were then dried under reduced pressure in a freeze-dryer, after which they were sintered with heating. Compared with conventional heat-based drying, the resulting pores were more spherical, which increased both the mechanical strength and porosity of the β-TCP. These materials had a wide range of pore sizes from 50 to 200 µm, with the mean and median values both approximately 100 µm regardless of the freeze-drying conditions. Mercury porosimetry data showed that the samples contained small, interconnected pores with sizes of 1.24 ± 0.25 µm and macroscopic, interconnected pores of 25.8 ± 4.7 µm in size. The effects of nonionic surfactants having different hydrophilic/lipophilic balance (HLB) values on foaming and pore size were also investigated. Materials made with surfactants having lower HLB values exhibited smaller pores and lower porosity, whereas higher HLB surfactants gave higher porosity and slightly larger macropores. Even so, the pore diameter could not be readily controlled solely by adjusting the HLB value. The findings of this work indicated that high porosity (>75%) and good compressive strength (>2 MPa) can both be obtained in the same porous material and that foaming agents with HLB values between 12.0 and 13.5 were optimal. [ABSTRACT FROM AUTHOR]

[Display omitted] Surfactants are inexpensive chemicals with promising applications in virus inactivation, particularly for enveloped viruses. Yet, the detailed mechanisms by which surfactants deactivate coronaviruses remain underexplored. This study delves into the virucidal mechanisms of various surfactants on Feline Coronavirus (FCoV) and their potential applications against more pathogenic coronaviruses. By integrating virucidal activity assays with fluorescence spectroscopy, dynamic light scattering and laser Doppler electrophoresis, alongside liposome permeability experiments, we have analyzed the effects of non-ionic and ionic surfactants on viral activity. The non-ionic surfactant octaethylene glycol monodecyl ether (C 10 EO 8) inactivates the virus by disrupting the lipid envelope, whereas ionic surfactants like Sodium Dodecyl Sulfate and Cetylpyridinium Chloride predominantly affect the spike proteins, with their impact on the viral membrane being hampered by kinetic and thermodynamic constraints. FCoV served as a safe model for studying virucidal activity, offering a faster alternative to traditional virucidal assays. The study demonstrates that physicochemical techniques can expedite the screening of virucidal compounds, contributing to the design of effective disinfectant formulations. Our results not only highlight the critical role of surfactant-virus interactions but also contribute to strategic advancements in public health measures for future pandemic containment and the ongoing challenge of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

The strategy of integrating water injection and chemical additives in combining secondary and tertiary oil recovery techniques has been widely investigated in enhancing oil recovery efficiency. Nevertheless, there is a lack of sufficient evidence on the effectiveness of a mixture of cationic and nonionic surfactants combined with water injection techniques in enhancing recovery in the application of carbonate reservoirs. Therefore, it is particularly critical to explore the impact of this combination strategy in enhancing recovery in fractured carbonate reservoirs. The recovery enhancement effect can be assessed by conducting phase behavior experiments and determining interfacial tension and contact angle. Further, the effectiveness of specific surfactant ration solutions in enhancing recovery can be verified by performing drive-off experiments. The results show that low mineralization water and surfactants have a significant synergistic effect in enhancing the recovery efficiency of carbonate reservoirs, with the optimal ratio of cationic to non-ionic surfactants being 2.5:1. The optimized surfactant ratio is able to increase the recovery of carbonate reservoirs by 20% compared to the original recovery rate. [ABSTRACT FROM AUTHOR]

This research aimed to design biocompatible polymeric surfactants as additives to natural rubber latex (NRL) and the mechanical properties of the latex films were evaluated thereafter. Both anionic and non-ionic surfactants, APS and NPS, were successfully synthesised from palm-based oleic acid by polyesterification, with their ester linkages verified by FTIR analysis. Both surfactants possess good thermal stability with thermal decomposition temperatures above 200 °C. They were biocompatible and non-cytotoxic, as evidenced by high cell viability > 80% for all tested cell lines. In general, the antibacterial activities of both surfactants were stronger against Gram-positive bacteria than Gram-negative bacteria. Surfactant solutions were prepared and compounded into NR latex to produce latex films. Both solutions exhibited good wetting properties with contact angles < 90°, low critical micelle concentration values ranging from 0.005 to 0.007 mol/L, low foaming ability, and reasonable foam stability above 80%. The unaged NR films compounded with APS demonstrated greater mechanical strengths than the control and NPS, recording the highest tensile strength of 28.65 MPa and the lowest modulus (M300) reflecting softness. Both latex films showed a slight reduction in mechanical properties after ageing. These results indicated that APS had a higher potential to modify NR latex film properties, in particular film softness. The surfactants also presented high potential as non-cytotoxic antimicrobial agents in NR compounding. [ABSTRACT FROM AUTHOR]

Water and several chemicals, including dyestuffs, surfactants, acids, and salts, are required during textile dyeing processes. Surfactants are harmful to the aquatic environment and induce several negative biological effects in exposed biota. In this context, the present study aimed to assess acute effects of five surfactants, comprising anionic and nonionic classes, and other auxiliary products used in fiber dyeing processes to aquatic organisms Vibrio fischeri (bacteria) and Daphnia similis (cladocerans). The toxicities of binary surfactant mixtures containing the anionic surfactant dodecylbenzene sulfonate + nonionic fatty alcohol ethoxylate and dodecylbenzene sulfonate + nonionic alkylene oxide were also evaluated. Nonionic surfactants were more toxic than anionic compounds for both organisms. Acute nonionic toxicity ranged from 1.3 mg/L (fatty alcohol ethoxylate surfactant) to 2.6 mg/L (ethoxylate surfactant) for V. fischeri and from 1.9 mg/L (alkylene oxide surfactant) to 12.5 mg/L (alkyl aryl ethoxylated and aromatic sulfonate surfactant) for D. similis, while the anionic dodecylbenzene sulfonate EC50s were determined as 66.2 mg/L and 19.7 mg/L, respectively. Both mixtures were very toxic for the exposed organisms: the EC50 average in the anionic + fatty alcohol ethoxylate mixture was of 1.0 mg/L ± 0.11 for V. fischeri and 4.09 mg/L ± 0.69 for D. similis. While the anionic + alkylene oxide mixture, EC50 of 3.34 mg/L for D. similis and 3.60 mg/L for V. fischeri. These toxicity data suggested that the concentration addition was the best model to explain the action that is more likely to occur for mixture for the dodecylbenzene sulfonate and alkylene oxide mixtures in both organisms. Our findings also suggest that textile wastewater surfactants may interact and produce different responses in aquatic organisms, such as synergism and antagonism. Ecotoxicological assays provide relevant information concerning hazardous pollutants, which may then be adequately treated and suitably managed to reduce toxic loads, associated to suitable management plans. [ABSTRACT FROM AUTHOR]

This paper investigates the physical mechanism underlying the effect of the concentration of nonionic surfactant on transparent electrophoretic displays, with a focus on particle charging and charge transport. Besides, a model of particle dynamics is also provided to validate the proposed surfactant influencing mechanism. [ABSTRACT FROM AUTHOR]

Due to their unique functional properties, nanoemulsions help enrich many hydrophobic compounds in water‐based beverages. In this study, using two nonionic surfactants (Tween 40 and Tween 80), separately, nanoemulsions containing Nigella Sativa L. oil were prepared by ultrasound method and tested to determine their size, polydispersity index, morphology, turbidity, and stability during 60 days of storage. In this study, the type of nonionic surfactants used significantly affected the average droplet diameter in the formed systems. Hence, Tween 40 produced tiny droplets, while using Tween 80 produced larger droplets. The comparison of the mean particle sizes by the Duncan method at a 95% confidence level showed that the effect of different surfactant concentrations (2, 4, 6, and 8 wt%) on the particle size was significant. The results showed that the lowest particle size corresponding to the formulation with 4 wt% Tween 40 and the 15‐min sonication was 59.2 nm, and the particle size distribution was monomodal. The results indicated that in the absence of a cosurfactant (glycerol), both pasteurization and boiling processes increased in particle size. However, adding glycerol before the thermal process improved the thermal stability of the samples. The results of this study revealed that ultrasound could be used to prepare nanoemulsions with microscopic particles in the nanometer size without high concentrations of synthetic surfactants. [ABSTRACT FROM AUTHOR]

Diesel engines are known for their excellent efficiency and are therefore used in a variety of applications. However, they are also one of the main sources of hazardous emissions such as nitrogen oxides (NOx) and smoke. Water-in-Diesel Emulsion (WiDE) is an alternative fuel that can possibly reduce some of the pollutant emissions without compromising engine performance. The surfactant formulation for WiDE usually follows the one used in water-in-oil (w/o) emulsions, where low hydrophilic–lipophilic balance (HLB) emulsifiers are preferred for better solubility in the diesel phase and stabilization at storage temperatures. However, by using a hydrophilic blend with a non-ionic surfactant, it is possible to develop an optimized formulation at higher fuel temperatures, which occur during an engine's operating condition, achieving possibly higher benefits. Across the different speeds, the results for the emulsion show 7.57% mean improvement in specific fuel consumption (SFC), 19.14% mean improvement in thermal efficiency (TE), 5.54% mean reduction in carbon dioxide (CO2), 20.50% mean reduction in nitric oxide (NO) and 75.19% mean reduction in smoke levels. However, carbon monoxide (CO) and hydrocarbons (HC) emissions were higher, with a mean increase of 81.09% and 93.83%, respectively. [ABSTRACT FROM AUTHOR]

Current methods to develop surfactant phase diagrams are time-intensive and fail to capture the kinetics of phase evolution. Here, the design and performance of a quantitative swelling technique to study the dynamic phase behavior of surfactants are described. The instrument combines cross-polarized optical and short-wave infrared imaging to enable high-resolution, high-throughput, and in situ identification of phases and water compositions. Data across the entire composition spectrum for the dynamics and phase evolution of a binary aqueous non-ionic surfactant solution at two isotherms are presented. This instrument provides pathways to develop non-equilibrium phase diagrams of surfactant systems—critical to predicting the outcomes of formulation and processing. It can be applied to study time-dependent material relationships across a diverse range of materials and processes, including the dissolution of surfactant droplets and the drying of aqueous polymer films. [ABSTRACT FROM AUTHOR]

Spray dust suppression is a primary technological method for controlling coal mine dust. To enhance the wetting and adhesion of droplets to dust particles and improve the efficiency of spray dust suppression, a method of synergistic dust reduction by micro-nano bubbles (MNBs) and surfactants is proposed. This research focuses on MNBs, three different types of surfactants, and low-wetting anthracite coal. Experimental analysis is conducted to investigate the interaction between surfactants and MNBs in solution. The wetting capability of dust particles by the mixed solution of MNBs and surfactants is studied. Additionally, a spray dust suppression experimental platform is employed to compare the dust reduction efficiency of different types of surfactants in synergy with MNBs. The experimental results indicate that surfactants facilitate the generation of nanoscale bubbles, reduce the average diameter of MNBs, and the charge carried by surfactant molecules affects the potential of MNBs. Anionic surfactants decrease the bubble potential, while cationic surfactants elevate it, with non-ionic surfactants having a minimal impact on bubble potential. The presence of MNBs can temporarily reduce the surface tension of a surfactant solution, bringing it to the surface tension at the critical micelle concentration (CMC) but cannot surpass the surface tension beyond the CMC. The addition of low-concentration surfactant solutions to bubbles decreases the contact angle between dust particles and coal dust, while high-concentration surfactant solutions have the opposite effect. In general, the combined use of MNBs and surfactants is beneficial for improving spray dust suppression efficiency. However, extremely high surfactant concentrations lead to an excessive absolute value of bubble potential, enhancing the stability between dust particles and reducing dust suppression efficiency. [ABSTRACT FROM AUTHOR]

The aggregation behavior of mixed micellar solutions based on 2-hydroxyethylpiperidinium surfactants and nonionic surfactant Brij® 35 was investigated. The critical micelle concentrations determined by varying the component ratio suggest a negative deviation from the ideal mixing model (synergistic effect). It was demonstrated that the magnitude of the deviation from ideal mixing behavior depends on the alkyl chain length in the cationic surfactant and on the component ratio. The solubilization effect of the binary systems on hydrophobic substances was evaluated taking Orange OT dye and ibuprofen drug as examples. It was found that the piperidinium surfactants studied, both individually and in compositions containing up to 50% of the nonionic surfactant, exhibit high antimicrobial activity comparable to that of commercial antibiotics. [ABSTRACT FROM AUTHOR]

Aqueous solutions of humic acid (HA) derivatized by a catalyzed O-alkylation reaction with methyl, pentyl, and benzyl groups at 40, 60, and 80% of total HA acidity were used to wash off polycyclic aromatic hydrocarbons (PAHs) from two contaminated soils. The enhanced surfactant properties enabled the alkylated HA to remove phenanthrene, anthracene, fluoranthene, and pyrene from both soils more extensively than the original unmodified HA, the 60% benzylation generally showing the greatest soil washing efficiency. For both soils, all alkylated HA revealed greater PAH removals than Triton X-100 nonionic surfactant, while the benzylated and methylated HA nearly and fully matched pollutants release by the anionic SDS in the coarse- and fine-textured soils, respectively. A consecutive second washing with 60% benzylated HA removed additional PAHs, in respect to the first washing, from the coarser-textured soil, except for fluoranthene, while removal from the finer-textured soil incremented even more for all PAHs. These findings indicate that the enhanced hydrophobicity obtained by a simple and unexpensive chemical derivatization of a natural humic surfactant can be usefully exploited in the washing of polluted soils, without being toxic to the soil biota and by potentially promoting the subsequent bio-attenuation of organic pollutants. [ABSTRACT FROM AUTHOR]

The current study reports the results of non‐aqueous dyeing on polyamide fabrics based on a reverse micellar system composed of a stable emulsion of soybean oil, a co‐surfactant, a nonionic surfactant and acid dyes. The system does not make use of water or electrolytes and significantly reduces the dyebath volume. The influence of the hydrophilic lipophilic balance of the surfactants was evaluated, and it was found that the more hydrophilic the surfactant, the better the interaction of the reverse micellar emulsion with the substrate and, consequently, the greater the resulting colour strength. The co‐surfactant plays an important role in the system, as its proportion to the surfactant/oil mixture is directly related to better exhaustion of the dyebath. The results were compared with those from a conventional water‐based dyeing system. Colour matching was performed using the CIELab colour difference formula (ΔE) measured by a reflectance spectrophotometer. [ABSTRACT FROM AUTHOR]

Ropinirole is a non-ergolinic dopamine agonist used to manage Parkinson's disease and it is characterized by poor oral bioavailability. This study aimed to design and develop advanced drug delivery systems composed of poloxamer 407, a non-ionic surfactant (Tween 80), and cyclodextrins (methyl-β-CD or hydroxy-propyl-β-CD) for possible brain targeting of ropinirole after nasal administration for the treatment of Parkinson's disease. The hybrid systems were formed by the thin-film hydration method, followed by an extensive physicochemical and morphological characterization. The in vitro cytotoxicity of the systems on HEK293 cell lines was also tested. In vitro release and ex vivo mucosal permeation of ropinirole were assessed using Franz cells at 34 °C and with phosphate buffer solution at pH 5.6 in the donor compartment, simulating the conditions of the nasal cavity. The results indicated that the diffusion-controlled drug release exhibited a progressive increase throughout the experiment, while a proof-of-concept experiment on ex vivo permeation through rabbit nasal mucosa revealed a better performance of the prepared hybrid systems in comparison to ropinirole solution. The encouraging results in drug release and mucosal permeation indicate that these hybrid systems can serve as attractive platforms for effective and targeted nose-to-brain delivery of ropinirole with a possible application in Parkinson's disease. Further ex vivo and in vivo studies to support the results of the present work are ongoing. [ABSTRACT FROM AUTHOR]

The surface tension of monolayers with mixtures of anionic and nonionic surfactant at the liquid/vapour interface is studied. Previous works have observed that calculations of the surface tension of simple fluids show artificialoscillationsforsmallinterfacialareas,indicatingthatthesurfacetensiondatafluctuateduetothefinite size effects and periodic boundary conditions. In the case of simulations of monolayers composed of surfactant mixtures,thesurfacetensionnotonlyoscillatesforsmallareasbutcanalsogivenon-physicaldata,suchasnegativevalues. Analysisofthemonolayerswithdifferentsurfactantmixtures,ionic(DTAB,CTAB,SDS)andnonionic (SB3-12), was done for density profiles, parameters of order and pair correlation functions for small and large box areas and all of them present similar behaviour. The fluctuations and the non-physical values of the surface tension are corrected when boxes with large interfacial areas are considered. The results indicate that in order to obtain reliable values of the surface tension, in computer simulations, it is important to choose not only the correct force field but also the appropriate size of the simulation box. [ABSTRACT FROM AUTHOR]

In this study, an evaluation of washing-based treatment for diesel-contaminated soil using non-ionic surfactants such as Tween-20, NP-9.5, and Triton X-100 at 5% (v/v) dosage for three days of washing in removing diesel as well as improvement of geotechnical properties was performed. The initial diesel content of 0.8 mg/g was identified using the gravimetric method in the soil. The geotechnical test results of the surfactant-washed diesel-contaminated soil show an increase in shear strength, a decrease in compression, and swelling. The contaminated and treated soil samples are also subjected to instrumental techniques like X-ray diffraction (XRD) and Fourier transform infrared radiation (FTIR). On analyzing the results from FTIR spectra, NP-9.5 is found to be the most efficient surfactant in removing the diesel. This study establishes that surfactant-aided soil washing is a prospective method for enhanced removal of diesel and leads to significant improvement in geotechnical properties of the treated soil. [ABSTRACT FROM AUTHOR]

Wetting the surface area of an electrode material as completely as possible is desirable to achieve optimum specific capacity of an electrode material. Keeping this surface area utilized even at high current densities and even when inside pores is required for high capacitance retention. The addition of surfactants at very small concentrations to aqueous supercapacitor electrolyte solutions has been suggested as a way to improve performance in terms of capacitance, capacitance retention at increased current density and stability. Effects are pronounced with carbon materials used in electrochemical double-layer capacitors; they are also observed with redox materials. The causes of the observed improvements and mode of operation of the added surfactants seem to need further investigation; they are inconclusive beyond the obvious statement of increased wetting. Reported examples and the current state of understanding are reviewed. [ABSTRACT FROM AUTHOR]

PLA/nanofibrillar cellulose (NFC) composite films were produced by solution casting. Before use, the cellulose fibers were modified with various types of surface active agents - cationic, anionic and non-ionic surfactants. The structure and morphology of samples of the cellulose fillers and composite films with polymer were analyzed by means of scanning electron microscopy and PXRD diffraction. Thermal parameters of the composite films were characterized by differential scanning calorimetry and thermogravimetric analysis. The tensile strength and elongation at break of the films were evaluated in mechanical tests. The ability to disintegrate of all PLA/NFC composites under composting conditions was also determined and compared. [ABSTRACT FROM AUTHOR]

In this work, the effects of solvent type and surfactant (porogen) on the properties of porous methyl-modified spin-on films were investigated. A qualitative assessment of the defectivity of the formed films was carried out. The refractive index, dielectric permittivity, and porosimetric properties of the films were analyzed using the method of spectral ellipsometry, frequency dependence of capacitance analysis, and porosimetry. It was found that the film properties depend more strongly on the surfactant type than on the solvent type. The highest porosity value is obtained with the use of nonionic surfactant Brij® 76, which has a higher molecular weight. At the same time, at lower molecular weight, the ionic surfactant CTAB provides comparable porosity. Despite the high porosity, samples from film-forming solutions containing CTAB do not exhibit a lower dielectric constant, which is presumably due to their hydrophilicity or porogen residue. The lowest value of the dielectric constant k ≈ 2.1 is typical for films made from film-forming solutions containing Brij® 76. The application of other porogens allows us to obtain a k value ~2.3–2.4. [ABSTRACT FROM AUTHOR]

The interaction of anionic silica nanoparticles with nonionic decaethylene glycol mono-dodecyl ether (C12E10) and ionic surfactants [both anionic sodium dodecyl sulfate (SDS) and cationic dodecyl trimethyl ammonium bromide (DTAB)] has been studied by small-angle neutron scattering and dynamic light scattering. The nonionic and cationic surfactant micelles are adsorbed on nanoparticles, whereas no adsorption of SDS surfactant micelles on nanoparticles is observed. The adsorption of C12E10 micelles provides additional steric stability to nanoparticles. However, the adsorption of cationic micelles leads to micelles-mediated fractal aggregation of nanoparticles. In the case of SDS surfactant, nanoparticles and micelles coexist in the solution. Furthermore, the adsorption behavior of surfactant micelles on nanoparticles has been tuned using a combination of nonionic and ionic surfactants. The combination of nonionic C12E10 with anionic SDS makes surfactant micelles to desorb from nanoparticles, whereas the combination of nonionic C12E10 with cationic DTAB leads to fractal aggregation of nanoparticles. The systematic transitions of micelle adsorption to desorption on nanoparticles with a C12E10–SDS mixed surfactant system and the aggregation of nanoparticles in a C12E10–DTAB mixed surfactant system as a function of ionic surfactant (SDS or DTAB) concentration have been examined. The micelles desorption from nanoparticles follows an exponential decay behavior with an increase in SDS concentration in C12E10–SDS, whereas the aggregate size shows an exponential growth with DTAB in C12E10–DTAB. The electrostatic interactions between nanoparticles and surfactant micelles are found to be dominating for tuning these transitions. [ABSTRACT FROM AUTHOR]

The chemical-enhanced oil recovery (CEOR) method is applied to change reservoir rock or fluid characteristics by injecting alkaline, surfactant, and polymer or a combination of two or three of the compounds. Surfactant flooding improves oil recovery by reducing the interfacial tension between oil and water. Selecting reservoir surfactants, especially microemulsions, requires careful screening. This study predicted waxy oil system interfacial tension using surfactant mixtures at below- and above-optimum salinity. To predict the interfacial tension, microemulsion types, HLB, ideal salinity, and HLD were used. The study predicted oil-surfactant-water interfacial tension using SAE, FEO, and their mixtures. We improved the Huh equation by adding a fitting parameter, β, to accommodate the transition from type III to type II microemulsions as salinity increases. With increasing salinity, anionic surfactant's hydrophilic-hydrophobic interactions change, affecting the CH0 values and surfactant layer thickness. This study improved hydrophilic-lipophilic deviation (HLDN) by establishing a fixed interval for nonionic surfactants. Van der Waals attraction, CH0 values and interface surfactant layer thickness are connected, reflecting the fact that lower CH0 values reduce interfacial tension better. This study also found that surfactant packing at the oil-water interface increases the order of the oil-solution ratio and the microemulsion values with polarity. [ABSTRACT FROM AUTHOR]

The antibacterial activity of surfactants is an important factor to consider for improving skin conditions in cosmetic and skin care products. In this study, we evaluated the antibacterial activity of 16 nonionic surfactants containing ethylene oxide, ester, and ether functional groups against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). 12:0 MG ester and 6–12 diol, which showed antibacterial activity against both Staphylococci, had compact hydrophilic groups with low polarity. In contrast, 12:0 PEG‐10 ester and 12:0 Sor ester, which showed antibacterial activity only against S. aureus, had large hydrophilic groups and high polarity. These results suggest that the hydrophilicity and polarity of the surfactant may be involved in its antibacterial behavior against Staphylococci. These findings will be useful in the design of surfactant molecules and in the development of cosmetics and body cleansers that exhibit antibacterial activity only against S. aureus. [ABSTRACT FROM AUTHOR]

As a new type of flooding technology, the application of nano-surfactant fluids in the petroleum industry has received much attention in recent years. Stability of the nanofluids, which requires the nanoparticles to remain dispersed in the base fluid during flowing in porous media, is vital for enhanced oil recovery (EOR). In this paper, the feasibility of using amphoteric surfactants to promote the dispersion stability of TiO2 nanoparticles in aqueous solution for EOR was investigated for the first time. The dispersion effects of four major classes of surfactants (cationic, anionic, non-ionic, and amphoteric) on TiO2 nanoparticles were compared. When the ultrasonication time was 10 min, the concentration of TiO2 nanoparticles and surfactant was 0.002 and 0.1 wt%, respectively, and the amphoteric surfactant disodium cocoamphodiacetate (CAD) had better dispersion stability for TiO2 nanoparticles compared with other surfactants. The Zeta potential of the CAD/TiO2 dispersion system was −47.53 mV, and the average particle size was 40 nm. Moreover, a nanofluid flooding system of CDEA-CAD/TiO2, with good dispersion stability and remarkable oil displacement performance, was constructed by compounding CAD with the non-ionic surfactant alkanolamide (CDEA). In the core flooding test, the CDEA-CAD/TiO2 nanofluid effectively enhanced oil recovery by 13.3%, which was mainly attributed to the outstanding wettability reversal, interfacial and emulsifying properties of the nanofluid. This study would help further supplement the research on the dispersibility of TiO2 nanoparticles and construct an efficient nanofluid flooding system to enhance oil recovery. This work mainly explored the feasibility of amphoteric surfactants to improve the dispersion stability of TiO2 nanofluids. A nanofluid flooding system based on amphoteric surfactants and TiO2 nanoparticles with stable dispersion and remarkable oil displacement performance was constructed. [ABSTRACT FROM AUTHOR]

Introduction Diclofop-methyl is labeled for use in wheat and barley to control many grassy species, e.g., the genus Avena. Efforts should be made to use diclofop-methyl correctly, allowing the reduced doses to be applied. The response of herbicides to spray volume is different. After determining a suitable spray volume for a foliage-applied herbicide, the next step is to adjust it. The spray volume can be adjusted by two methods: the change in application speed or nozzle size. If less spray volume is necessary to apply an herbicide, it is needed to increase application speed. It causes the spray droplets to be more bounced or shattered from the leaf surface, causing the herbicide not to achieve optimal efficacy. Therefore, selecting a smaller orifice nozzle is much more applicable, of course, if the spray drift is controlled. The surface tension of water, which is used to spray herbicides, can be slightly reduced after adding the formulation of herbicides. Therefore, the relatively high surface tension of the spray solution poses three main problems. First, the spray droplets can easily be bounced off the leaf surface. Second, those remaining on the leaf surface after impact have a relatively spherical shape. Third, the crystalline wax in the cuticles, is considered an essential barrier to penetrating herbicides into the leaf tissues. It is wellestablished that the three main issues mentioned above can be addressed by selecting a suitable surfactant to add to the spray solution. This addition enables optimal efficacy of the herbicide. Consequently, numerous previous studies have highlighted the superiority of trisiloxane surfactants over non-silicone surfactants in enhancing herbicidal activity. This study aims to assess whether the effect of spray volume, adjusted by changing nozzle size, on the herbicidal activity of diclofop-methyl could be influenced by two types of trisiloxane surfactants -- one with super wetting properties and the other with non-super wetting properties. Materials and Methods A greenhouse trial was performed as a dose-response relationship at the Bu-Ali Sina University, Hamedan, Iran. The experiment was designed as a four-factor completely randomized design. The first factor was the dose of diclofop-methyl (Illoxan® EC 36%) including 0, 112.5, 225, 450, 900 (labeled dose), and 1350 g ha-1. The second factor was spray volume, including 60, 120, 240, and 480 L ha-1, which were adjusted using 1100075, 110015, 11003, and 11006 flat fan nozzle, respectively. The third factor was two types of trisiloxane surfactants, Break-Thru® S 233 having a non-super wetting property and Break-Thru® S 240 having a super wetting property. Both are non-ionic surfactants and manufactured by Evonik company in Germany. They formed their critical micelle concentration (CMC) at 0.1% v v-1 at which the surface tension of distilled water (72.1 mN m-1) containing Break-Thru® S 233 and Break-Thru® S 240 was measured to be 24.1 and 22.6 mN m-1, respectively. The fourth factor was surfactant concentration, including 0, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, and 0.8% v v-1 (a range from ⅛ to 8 CMC, respectively). A compressor sprayer was used to apply the treatments at 300 kPa spray pressure. A nonlinear regression analysis was conducted to analyze the 'drc' using the software R. Results and Discussion A 40% increase in the ED50 value occurred with increasing the spray volumes from 60 to 480 L ha-1 (536.4 and 865.1 g ha-1, respectively), indicating a negative relationship between diclofop-methyl activity and spray volume. Adding Break-Thru® S 233 at 0.025% v v-1 to 60, 120, 240, and 480 L ha-1 spray volumes caused a 1.16, 3.31, 2.04, and 2.13-fold decrease in the ED50 value compared with no surfactant at their corresponding spray volumes, respectively. While, adding Break-Thru® S 240 at 0.025% v v-1 to 60, 120, 240, and 480 L ha-1 spray volumes caused a 1.39, 1.32, 1.34, and 1.19-fold decrease in the ED50 value compared with no surfactant at their corresponding spray volumes, respectively. A decrease in the ED50, attributed to the addition of surfactants, signifies an enhanced activity of diclofop-methyl against sterile oat. This improvement may stem from a reduction in the surface tension of the spray solution, resulting in an expanded retention and/or spreading area of the spray droplets on the leaf surface. This, in turn, facilitates increased penetration of the herbicide into the leaf tissue. These findings indicate that Break-Thru® S 233 works better when added at low concentration to a lowvolume spray solution, while Break-Thru® S 240 works better when added at high concentration to a low-volume spray solution. It can be attributed to the difference in the wetting property of surfactants. The natural relationship between diclofop-methyl activity and spray volume at higher concentrations of Break-Thru® S 233 may be related to its phytotoxic effect, resulting in an antagonism effect on diclofop-methyl activity against sterile oat. In the case of Break-Thru® S 240, the relationship mode between diclofop-methyl activity and spray volume was not affected by surfactant concentration indicating the lack of phytotoxic effect by this surfactant. Conclusion The current study revealed a negative relationship between diclofop-methyl efficacy and spray volume, which was adjusted by nozzle size. Although this finding differs from a previous study in which spray volume has been adjusted by application speed, they showed that the effect of spray volume on the herbicide's efficacy depends not only on herbicide but also on how it is adjusted. The smaller, more concentrated spray droplets are necessary to get a better action of diclofop-methyl against sterile oat. However, the negative relationship observed between diclofop-methyl efficacy and spray volume could also be observed with two types of trisiloxane when they surfactants, were used at 0.0125 to 0.1 v v-1. While, when they were used at 0.2 to 0.8% v v-1, the relationship mode changed from negative to neutral for Break-Thru® S 233, but it did not change for Break-Thru® S 240. Moreover, Break-Thru® S 240 works better when added at high concentration to a lowvolume spray solution due to the danger of spray run-off, while Break-Thru® S 233 works better when added at low concentration to a low-volume spray solution due to its phytotoxic effect. [ABSTRACT FROM AUTHOR]

The biodegradation of tar-rich coal in the Ordos Basin was carried out by Bacillus licheniformis (B. licheniformis) under actions of four kinds of surfactants, namely, a biological surfactant (Rh), a nonionic surfactant (Triton X-100), an anionic surfactant (LAS), and a cationic surfactant (DTAB). The biodegradation rates under the actions of Triton X-100, LAS, Rh, DTAB, and the control group (without surfactant) were 59.8%, 54.3%, 51.6%, 17.3%, and 43.5%, respectively. The biodegradation mechanism was studied by examining the influences of surfactants on coal samples, bacteria, and degradation products in the degradation process. The results demonstrated that Rh, Triton X-100, and LAS could promote bacterial growth, while DTAB had the opposite effect. Four surfactants all increased the cell surface hydrophobicity (CSH) of B. licheniformis, and Triton X-100 demonstrated the most significant promotion of CSH. The order of improvement in microbial cell permeability by surfactants was DTAB > TritonX-100 > LAS > Rh > control group. In the presence of four surfactants, Triton X-100 exhibited the best hydrophilicity improvement for oxidized coal. Overall, among the four surfactants, Triton X-100 ranked first in enhancing the CSH of bacteria and the hydrophilicity of oxidized coal and second in improving microbial cell permeability; thus, Triton X-100 was the most suitable surfactant for promoting B. licheniformis's biodegradation of tar-rich coal. The GC-MS showed that, after the action of Triton X-100, the amount of the identified degradation compounds in the toluene extract of the liquid product decreased by 16 compared to the control group, the amount of dichloromethane extract decreased by 6, and the amount of ethyl acetate extract increased by 6. Simultaneously, the contents of alkanes in the extracts of toluene and dichloromethane decreased, lipids increased, and ethyl acetate extract exhibited little change. The FTIR analysis of the coal sample suggested that, under the action of Triton X-100, compared to oxidized coal, the Har/H and A(CH2)/A(CH3) of the remaining coal decreased by 0.07 and 1.38, respectively, indicating that Triton X-100 enhanced the degradation of aromatic and aliphatic structures of oxidized coal. Therefore, adding a suitable surfactant can promote the biodegradation of tar-rich coal and enrich its degradation product. [ABSTRACT FROM AUTHOR]

In this experiment, an unexampled oxidation of an aromatic alcohol (4-chlorobenzyl alcohol) was carried out by Cr(VI) in aqueous mixed micellar medium under pseudo-first-order reaction condition at 30 °C. The spectrophotometric kinetic study exhibited excellent relative catalytic performances of micro-heterogeneous micellar aggregation in single and mixed micellar media (using anionic SDS and nonionic TX-100 surfactants). In the perspective of reaction rate control, the CMC of surfactants (in single or mixed micellar form) was explored to play a significant role. Herein two organic hetero-aromatic promoters, Phen and Bpy, were also used to scrutinize their effect on reaction dynamics in both the micellar media. The fabrication of mixed micelle was confirmed by UV, 1H NMR and 2D NOESY study. [ABSTRACT FROM AUTHOR]

The self-assembly and phase separation of mixtures of polyelectrolytes and surfactants are important to a range of applications, from formulating personal care products to drug encapsulation. In contrast to systems of oppositely charged polyelectrolytes, in polyelectrolyte-surfactant systems the surfactants micellize into structures that are highly responsive to solution conditions. In this work, we examine how the morphology of micelles and degree of polyelectrolyte adsorption dynamically change upon varying the mixing ratio of charged and neutral surfactants. Specifically, we consider a solution of the cationic polyelectrolyte polydiallyldimethylammonium, anionic surfactant sodium dodecyl sulfate, neutral ethoxylated surfactants (C m EO n ), sodium chloride salt, and water. To capture the chemical specificity of these species, we leverage recent developments in constructing molecularly informed field theories via coarse-graining from all-atom simulations. Our results show how changing the surfactant mixing ratios and the identity of the nonionic surfactant modulates micelle size and surface charge, and as a result dictates the degree of polyelectrolyte adsorption. These results are in semi-quantitative agreement with experimental observations on the same system. [ABSTRACT FROM AUTHOR]

2,4,7,9-Tetramethyl-5-decyne-4,7-diol (TMDD) is a non-ionic surfactant with a wide range of applications. TMDD is considered a high-production chemical and, due to its low biodegradation rate, possesses a potentially high prevalence in the environment. However, despite its widespread use, toxicokinetic data and data on internal exposure to TMDD in the general population are completely lacking. Hence, we developed a human biomonitoring (HBM) method for TMDD. Our approach included a metabolism study with four subjects, who were administered an oral dose of 75 µg TMDD/kg body weight and a dermal dose of 750 µg/kg body weight. Terminal methyl-hydroxylated TMDD (1-OH-TMDD) was previously identified as the main urinary metabolite in our lab. The results of the oral and dermal applications were used to determine the toxicokinetic parameters of 1-OH-TMDD as a biomarker of exposure. Finally, the method was applied to 50 urine samples from non-occupationally exposed volunteers. Results show that TMDD was rapidly metabolized, with an average tmax of 1.7 h and a rapid and almost complete (96%) excretion of 1-OH-TMDD until 12 h after oral dosage. Elimination was bi-phasic, with half-lives of 0.75–1.6 h and 3.4–3.6 h for phases 1 and 2, respectively. The dermal application resulted in a delayed urinary excretion of this metabolite with a tmax of 12 h and complete excretion after about 48 h. The excreted amounts of 1-OH-TMDD represented 18% of the orally administered TMDD dose. The data of the metabolism study demonstrated a fast oral as well as substantial dermal resorption of TMDD. Moreover, the results indicated an effective metabolism of 1-OH-TMDD, which is excreted rapidly and completely via urine. Application of the method to 50 urine samples revealed a quantification rate of 90%, with an average concentration of 0.19 ng/mL (0.97 nmol/g creatinine). With the urinary excretion factor (Fue) derived from the metabolism study, we estimated an average daily intake of 1.65 µg TMDD from environmental and dietary sources. In conclusion, 1-OH-TMDD in urine is a suitable biomarker of exposure to TMDD and can be applied for biomonitoring of the general population. [ABSTRACT FROM AUTHOR]

1 g/L of different non-ionic surfactants i.e. BNO, bone glue, and sesbania gum and anionic surfactants i.e. NES, polyacrylamide (PAM), and sodium dodecylbenzenesulfonate (SDBS) were added individually to an electrolyte composed of 120 g/L methanesulfonic acid (MSA) and 10 g/L Sn2+ for electrodeposition of tin. The effects of the six kinds of surfactants on the electrodeposition behavior of tin in the MSA electrolyte, and the phase structure, surface morphology, and weldability of the tin coating obtained therefrom were studied by cyclic voltammetry, contact angle measurement, Hull cell testing, X-ray diffraction (XRD), scanning electron microscopy (SEM), and weldability testing. The results showed that all of the six surfactants can greatly improve the cathodic current efficiency and wettability of the electrolyte to copper substrate and the deposition rate of tin coating. Except for PAM, the said surfactants can inhibit the hydrogen evolution effectively. The electrolyte containing the anionic surfactant NES exhibited the best throwing power, the highest current efficiency, and the fastest deposition rate. The tin coating electroplated from it was smooth, fine-grained, and compact with the characteristic X-ray diffraction peaks of crystal planes (211), (112), and (321), and featured the best weldability. [ABSTRACT FROM AUTHOR]