Journal of Surfactants and Detergents最新文献

Gemini surfactants are dimeric molecules having two monomeric units connected by a spacer. Gemini surfactants, owing to their molecular structure have better surfactant properties than other monomeric surfactants. Esterquat class gemini surfactants can be synthesized using a spacer containing ester linkages. In the current study, the synthesis of novel esterquat gemini surfactants was carried out with spacers of varying chain lengths and was characterized using sophisticated instrumental methods. Various surfactant properties including foaming, emulsification, CMC, surface excess, antimicrobial activity and wetting potential using contact angle were analyzed and compared with benzalkonium chloride. It was observed that the CMC as low as 24.79 × 10⁻³ mM of the synthesized surfactants is potentially lower than that of conventional monomeric surfactants and was found to increase with an increase in spacer chain length. Further, the applicability and evaluation of performance properties of the synthesized surfactants were studied in fabric softener formulation. The water absorbency and whiteness retention of the formulation prepared using 12-6-12 GS was the highest due to its better wettability amongst other synthesized surfactants owing to its higher spacer chain length. To summarize, the surface and anti-microbial properties of the synthesized surfactants vary greatly with the alteration in spacer chain length.

Sulfur is a key element in most anionic surfactants. About 75% of sulfur currently is generated as a waste byproduct of petroleum refining, while most of the remainder is generated as a waste byproduct of natural gas refining. Assuming the world's fossil fuel use decreases in the future, what will happen with sulfur-containing surfactants? Three possible alternatives are explored. First, alternate sources of sulfur could replace sulfur from fossil fuel. Second, surfactants that do not contain sulfur could replace those that contain sulfur. Third, other industries could replace sulfur in their products, while sulfur remains in surfactants. Each of these will be considered, and predictions will be made in terms of the likeliest outcomes.

As the cosmetic market continues to transform, innovative ingredients such as biosurfactants (BS) emerge as a fundamental step towards a generation of cosmetic products characterized by efficacy, safety, and environmental responsibility. In alignment with the global push towards natural, renewable, and non-toxic materials, BS stands out as an interesting alternative to conventional synthetic surfactants. BS are a type of green surfactants and compared to synthetic surfactants derived from petroleum they are more biodegradable and have low or no toxicity. This work aimed to investigate the suitability of a biosurfactant extracted from the yeast Scheffersomyces shehatae (BS-SS) to be used in cosmetic applications. The cytotoxicity of the BS-SS was tested in fibroblast (L929) and keratinocyte (HaCaT) cell lines and the potential for ocular irritation was assessed by the hen's egg chorioallantoic membrane test (HET-CAM). The cleaning efficiency of the BS-SS was measured as the ability of make-up removal in pig skin. Our results showed that the IC 50 values were 10.49 mg/mL for fibroblasts and 11.77 mg/mL for keratinocytes, and the biosurfactant did not result in hemorrhage, lysis, and coagulation damages in the chorioallantoic membrane, which classifies the biosurfactant solution as non-irritant. Therefore, ocular toxicity and in vitro skin cell toxicity results showed that BS-SS can be tolerable and safe for cosmetic purposes. BS-SS featured promising cleaning properties, similar to the cleansing activity of the 1% SDS solution and of micellar water for lipstick and foundation products. In conclusion, the results indicate its potential use in cosmetic applications.

Nonionic-surfactants have been reported as nanocarriers for delivering low bioavailable drugs at the target sites. In the current study, two new nonionic surfactants were synthesized to enhance the oral bioavailability of the low water-soluble antifungal drug Amphotericin-B. The hemolysis effect of nonionic surfactants on red blood cells and cytotoxicity against the 3T3 cell line was studied. Both surfactants have shown low hemolysis and cytotoxicity as compared to standard Tween 80. The morphology of drug-loaded niosomes of nonionic surfactants 1 and 2 was studied by using atomic force microscopy (AFM), and both surfactants based vesicles were spherical, while their average sizes were measured by dynamic light scattering (DLS). The average size, zeta potential and polydispersity index (PDI) values of surfactants 1 and 2 were 282 ± 3 nm, −8 ± 1 mV, 0.26 and 287 ± 3 nm, −10 ± 1 mV, 0.24. The drug entrapment efficiency and critical micelle concentrations of nonionic surfactants were determined by using UV–visible spectroscopy. The structures of surfactants 1 and 2 were assessed through single-crystal x-ray crystallographic analysis, while Hirshfeld analysis was performed to study the intermolecular interactions of molecules, as well as the packing behavior of their crystals. The nonionic-surfactant 1 was further tested for antileishmanial activity against Leishmania tropica promastigotes, in both drug-loaded and unloaded niosomal vesicular forms. The nonionic surfactant 1 was found to be a potentanti-leishmanial agent in the drug-loaded form with IC₅₀ = 3.02 ± 0.91 μM in comparison to their standard drugs Amphotericin-B (IC₅₀ = 3.8 ± 0.04 μM) and miltefosine (IC₅₀ = 42.2 ± 0.6 μM) (p < 0.1). These results, therefore, form the basis of further results towards efficient drug delivery against tropical disease Leishmaniasis.

Sulfate surfactants in cosmetic products raise concerns due to their skin irritating impact and sustainability. Rhamnolipid, a green and safe biosurfactant, was studied from the perspective of rheology to help develop a formulation with natural and effective ingredients for cosmetics. The viscosity of rhamnolipids was investigated by changing pH, concentration and adding additives like inorganic salts (NaCl, MgCl₂) and polymers (Carbopol® Ultrez 20, Carbopol® Aqua SF-1, Carbopol® 940 and cationic guar gum), showing that the viscosity of rhamnolipid had a positive correlation with the increase of concentration, a negative correlation with the increase of pH, and that polymers instead of inorganic salts were suitable for thickening rhamnolipid. Further rheology tests indicated that Carbopol® Aqua SF-1 imparted gel properties of rhamnolipid while cationic guar gum determined the liquid properties. In addition, the rhamnolipid-containing moisturizing cream consisting of stearic acid/squalane ratios all showed shear-thinning and gel behavior the same as the commercial ones. Visual appearance and particle size analysis indicated that all formulations exhibited high storage stabilities. The knowledge gained from this study may be useful for designing “sulfonate-free” shampoo and cream with rheological properties that can be tailed for specific commercial cosmetic applications.

Mannosylerythritol lipids (MELs), a glycolipid biosurfactant, possess great potential in many high-value-added fields. However, its water-insolubility is an important obstacle to its wide application, especially in home and personal care fields. In this study, a new strategy “killing two birds with one stone” based on the chemical modification of natural MELs was developed for the preparation of hydrophilic MELs. These newly prepared MELs can be efficiently isolated from the reacted solution via stepwise extraction with a methanol/n-hexane system. 88% of hydrophilic MELs were recovered from natural MELs, with a corresponding yield of 50%. This is mainly attributed to the esterification of fatty acids, representing the main and relatively-difficult-to-remove impurities in fermentative-produced MELs, facilitating separation from the MEL product via extraction. Moreover, these new MELs presented comparable surface activities to natural MELs while exhibiting enhanced water solubility and biocompatibility. This originates from the generation of MEL-D, resulting from the deacetylation of natural MELs and the formation of new hydrophilic MELs containing just one hydrophobic chain (named “MEL-G”). Hence, the present strategy is not only beneficial for the removal of impurities (fatty acids) but also for the preparation of MELs with improved hydrophilicity.

In the current study, a tetracationic quaternary ammonium salt (TCQAC) was synthesized and characterized and its ability to suppress corrosion on mild steel (MS) in a 0.5 M H₂SO₄ solution was examined. Various chemical, electrochemical, and surface characterization techniques were utilized to study the inhibition efficiency of TCQAC. The TCQAC manifests 99.83% efficiency at 20 ppm concentration. Out of all the examined isotherm models, the Langmuir isotherm offered the best fit for the TCQAC adsorption on the MS surface. A very high negative value of ΔG_ads (−45.18 kJ mol⁻¹) suggests that the adsorption of TCQAC followed the chemisorption mechanism. Electrochemical studies indicate that TCQAC increases the linear and charge transfer resistances (LPR and R_ct, respectively). TCQAC slows down the anodic and cathodic Tafel reactions; however, it acts as an anodic-type inhibitor at 5, 10, and 20 ppm. The appearance of extra Cl and N signals in the energy dispersive x-ray (EDX) spectrum and an improvement in surface smoothness in the scanning electron microscope (SEM) image of the inhibited sample corroborated the adsorption method of corrosion inhibition. X-ray photoelectron spectroscopy (XPS) study indicates that TCQAC creates corrosion preventive layers by chemical adsorption. In Frontier molecular orbitals (FMOs), highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were delocalized around the central part that comprises two benzyls, four allyls, and one hydrocarbon ((CH₂)₆) moieties and two quaternary nitrogen atoms. The outcomes of XPS and density functional theory (DFT) analyses indicate that the chemisorption of TCQAC occurs by dπ–pπ bonding with the surface iron atoms. The π-electrons of aryl and allyl moieties extensively participate in the bonding.

The surface zeta potential (SZP) technique is a promising method for investigating the electrokinetic properties of various macroscopic surfaces. However, there have been no attempts as yet to use the SZP technique in the presence of surfactants. In this work, we studied the effect of classical low-molecular surfactants (SDS, АОТ, Triton X-100, and CTAB) on the properties of tracer particles with different size: commercial polystyrene (PSN, 27.2 ± 0.1 nm), “blue” colloidal (BI-ZR5, 191 ± 1 nm), and hydrophilic SiO₂ particles (520 ± 12 nm) obtained by quartz evaporation under the action of a relativistic electron beam. The initial charge of all the particles was negative. Anionic surfactants (АОТ and SDS) exerted virtually no effect on ζ-potential up to the concentration of 10⁻³ M and decreased it by ca. 27% at the concentration of 10⁻² M. Nonionic oxyethylated Triton X-100 increased ζ-potential but did not recharge the particles. Cationic CTAB recharged the surface of all the particles already at the concentration of 10⁻⁵ M; at 10⁻² M ζ-potential reached 39–65 mV. The possibility of applying BI-ZR5 as the tracer particles to estimate the electrokinetic potential of the borosilicate glass substrate in the presence of CTAB was demonstrated.