Journal of Surfactants and Detergents最新文献

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.

To enrich the clean fracturing fluid system with high temperature resistance, a novel tetrameric cationic surfactant (TET) was developed and used as a thickener and mixed with different concentrations of sodium salicylate (NaSal) to obtain a new clean fracturing fluid. The flow curves, thixotropy, viscoelasticity, temperature resistance property, and proppant-suspending capacity were further investigated. The rheological study showed that the Casson model could be used to accurately describe the flow curve of TET/NaSal micelle solutions and the addition of NaSal improved the thixotropy and viscoelasticity of surfactant solution. The optimal mass ratio of TET/NaSal solution was 5/1.5 wt%, and it had good proppant-suspending capacity. What is more, the retained viscosity of TET/NaSal (5/1.5 wt%) solution was 52.27 mPa·s after shearing at 140°C and 100.0 s⁻¹ for 65 min, which met industry requirements (viscosity > 20 mPa·s) of viscoelastic surfactant fracturing fluids. Moreover, the combination of 10 wt% TET aqueous solution with pH value of 8.51 and 2.6 wt% salicylic acid (HSal) suspension of the same mass significantly delayed micellar formation. The four-parameter rheo-kinetics model can be used to fit the viscosity curves of micellar formation, which provided the rheological basis for the study of delayed viscoelastic micellar formation.

High salinity has been a major challenge in oil recovery. Here, two binary systems composed of sodium fatty alcohol polyoxyethylene ether carboxylate (AECM) and cationic surfactants, cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPyCl) were developed. Their fundamental properties; namely, oil/water interfacial tension, wettability, emulsification, adsorption, and oil-washing were investigated and compared. The results showed that both AECM–CTAB (4:6–7:3, m/m) and AECM–CPyCl (5:5–6:4, m/m) could decrease oil/water interfacial tension below 10⁻² mN/m. Even the total salinity was close to 200,000 mg/L after 7 days of quartz sand adsorption, showing a good interfacial activity and excellent anti-adsorption properties. All these compound drives could effectively change the wettability of the glass surface, which reduced the contact angle to a minimum of 54.76°. In addition, the emulsification time could reach up to 24 h at 85°C, with excellent emulsification performance at high temperatures. The oil washing efficiency could reach 74.68% after 48 h. According to our comprehensive analysis, the best formulation was obtained at AECM/CTAB ratio of 5:5.

Carbon nanotubes (CNTs) are proving to be versatile nanomaterials that exhibit superior and attractive electrical, optical, chemical, physical, and mechanical properties. Different kinds of CNTs exist, and their associated properties have been actively explored and widely exploited from fundamental studies to practical applications. Obtaining high-quality CNTs in large volumes is desirable, especially for scalable electronic, photonic, chemical, and mechanical systems. At present, abundant but random CNTs are synthesized by various growth methods including arc discharge, chemical vapor deposition, and molecular beam epitaxy. An economical way to secure pristine CNTs is to disperse the raw soot of CNTs in solutions, from which purified CNTs are collected via sorting methods. Individual CNTs are generally hydrophobic, not readily soluble, requiring an agent, known as a surfactant to facilitate effective dispersions. Furthermore, the combination of surfactants, polymers, DNA, and other additives can enhance the purity of specific types of CNTs in confidence dispersions. With highly-pure CNTs, designated functional devices are built to demonstrate improved performance. This review surveys and highlights the essential roles and significant impacts of surfactants in dispersing and sorting CNTs.

Fundamental physical chemical properties of a monolayer film comprised of the chiral, photopolymerizable phospholipid 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (Diyne PC) and the impact of a model perfluorocarbon, perfluorotetradecanoic acid (PF), on these film properties have been investigated, both with and without UV photopolymerization. Enantiomerically pure Diyne PC formed compact, stable monolayers at the air-water interface, exhibited typical phospholipid phase transitions in surface pressure-area isotherms and yielded micron-scale, linear domains upon film compression. Photopolymerized films were significantly more expanded in comparison with the unpolymerized films and the resulting domains had a spiral morphology with a strongly preferred spiral direction. Mixing Diyne PC with PF altered the isotherm behavior, with the principal effects being a significant reduction in the plateau region associated with the characteristic LE-LC phase transition and no larger-scale spiral domain formation in the monolayers of the mixed films. Results are discussed in the context of interactions between the two different film components and the tendency of perfluorinated surfactants to disperse condensed phase regions of phospholipid-based monolayer films. Overall, the tendency of PF to disperse condensed regions of the film makes patterning of films in mixed phospholipid-perfluorocarbon monolayers particularly difficult.

More than 10 million tonnes of metal salts of fatty acids are manufactured worldwide every year, to create a range of soft condensed-matter cosmetic products such as bar soaps, liquid washes, deodorant sticks, skin creams, toothpastes, and so on. These salts, popularly known as soaps, mainly use palm or tallow-based oils as the source of fatty acids. Soap bars comprised of more than 80% soaps alone account for a significant part of the global oil/fat footprint in non-edible usage. The COVID pandemic highlighted the need for hygiene and germ protection, thereby driving the consumption of soap bars further. Providing these personal hygiene assets to all strata of society while minimizing the negative impact on the environment through increased material consumption is a critical challenge faced by the soap industry today. Considerable research is ongoing toward making more sustainable soap bars by reducing the use of oils/fats without compromising the sensory and functional performance. Another challenge faced is that in many geographies, soap bars must comply with regulatory standards which mandate minimum levels of oils/fats (called TFM—total fatty matter) in the product with no reference to the performance or benefits provided. What this paper will demonstrate is that there are technologies to manufacture soap bars that meet the desired product performance independent of the level of TFM. These technologies have the potential to provide formulation flexibility and environmental benefits by opening the ingredient space and cutting down significantly on greenhouse gas emissions through reduced consumption of oils.