Journal of Surfactants and Detergents最新文献

Deciphering the role of hydrophobicity of the capping ligands on the development of luminescent Metal Nanoclusters (MNCs) is a longstanding endeavor and demands more comprehensive scientific investigations. Hence, our attempts have been directed to explore this scarcely reported fact by adopting the rather non-conventional top-down approach for the development of MNCs. Herein, we are reporting the synthesis of the highly stable Cysteamine-templated gold nanoclusters (AuNCs) with different photophysical properties from the core etching of bile salts-templated Metal Nanoparticles (MNPs). Herein, we have used three different bile salts (sodium cholate, NaC; sodium taurocholate, NaTC; and sodium deoxycholate, NaDC) with varying hydrophobicity index. The role of hydrophobicity of the bile salts (NaDC > NaC > NaTC) had a profound influence on the synthesis of the AuNPs, as well as in the synthesis of AuNCs by the core etching of different AuNPs. It was observed that the core etching of these three AuNPs, templated by NaC (NP1), NaDC (NP2), and NaTC (NP3) with a common etching agent cysteamine, leads to the formation of three AuNCs (Cystm@AuNC1 derived from NP1, Cystm@AuNC2 derived from NP2, and Cystm@AuNC3 derived from NP3) characterized by different photophysical signatures.

Nano depressurization and injection enhancement are important issues to alleviate the problems of injection volume reduction and recovery reduction in the development of an oilfield waterflooding process. However, there are few depressurization reports about hydrophobic organic nano materials in nano depressurization technology. In this study, a hydrophobic polystyrene nanoparticle (32.2 nm) was prepared as a depressurization agent. A novel polyoxyethylene ether-modified betaine surfactant (AEC-SBe) was synthesized to improve the dispersion stability, depressurization, and injection augmentation of hydrophobic polystyrene nanoparticles. The composite system demonstrated a 48.91% reduction in water injection pressure and exhibited good stability at 95 °C, outperforming both the individual AEC-SBe and typical hydrophobic nano SiO₂. The combined effects of low interfacial tension (of the order of 10⁻² mN/m), a high anti-swelling rate (95%), and alterations in rock surface wettability are considered to be the primary mechanisms contributing to the good depressurization effect observed. This work offers theoretical support for the efficient development of medium–low permeability reservoirs by introducing effective reagents.

Polymeric surfactants, valued for their ability to stabilize interfaces and tunable self-assembled structures, find extensive applications in personal care, drug delivery, pharmaceuticals, and industrial formulations. To develop an efficient polymeric surfactant, herein we investigate the synthesis and characterization of side-chain poly(ethylene glycol) (PEG)-based homopolymers (PPEGMAx), using reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of a hydrophobic tail-functionalized chain transfer agent (CTA), enabling precise control over molar mass and narrow dispersity (Đ). Structural confirmation and compositional analysis are performed using ¹H nuclear magnetic resonance (¹H NMR) spectroscopy. The amphiphilic nature and self-assembly behavior of the polymers are investigated through fluorescence spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM). The polymers show critical aggregation concentrations in the range 27–63 μg/mL in water, with sizes ranging from 40 to 80 nm. However, a suitable hydrophobic/hydrophilic balance in the polymer structure is necessary for the aggregation behavior to develop their potential as polymeric surfactants.

Formulating cosmetic products to meet consumer expectations poses significant challenges in terms of stability and shelf life. This work evaluates cosmetic emulsions formulated with three commercial emulsifiers: Polyglyceryl-3 distearate (Dermofeel®, a biobased surfactant), Glyceryl stearate (50%)/PEG-100 stearate (50%) (Lipomulse®, a nonionic mixture of glyceryl and ethoxylated surfactants), and Potassium cetyl phosphate (Amphisol K®, an anionic surfactant). Additionally, three emollients, namely Caprylic/Capric Triglyceride, Isoamyl Cocoate, and Jojoba Oil, were incorporated into the formulations. The effect of emulsion composition on stability, droplet size, rheology, and texture was systematically assessed via experiments and multivariate regression modeling, thereby providing an objective tool for cosmetic emulsions formulation. The lifetime of emulsions showed that emulsions containing Potassium cetyl phosphate exhibited separation velocities larger than 60 μm/s, whereas those with the other emulsifiers showed separation velocities below 40 μm/s, indicating larger lifetimes. A predictive model based on a statistical simplex centroid experimental design was developed to evaluate the separation velocity of emulsions based on the composition of the system, enabling the assessment of important variables that influence emulsion stability. The results indicate that composition variables (such as oil concentration) and formulation variables (such as surfactant nature and oil type) are important in determining emulsion stability, but also secondary effects such as surfactant-emollient interactions are crucial to predict the lifetime of cosmetic emulsions.

Nonionic surfactant vesicles (Niosomes) were prepared using a surfactant polyoxyethylene (10) stearyl ether [Brij S10] having a high hydrophile: lipophile balance (HLB). Optical and electron microscopy and light scattering indicate the stability of these vesicles. To propose the niosomal vesicles as future drug delivery systems (DDS), the morphology and bilayer characteristics of the niosomes have to be studied in detail. Insight into the niosomes could be obtained by fluorescence probing of xanthene dye aggregation. The use of Xanthene dye aggregation to probe the vesicular microenvironment has not hitherto been reported. Subsequently, we studied the entrapment and release behavior of these vesicles. The potentiality of these niosomes to entrap and release a real chemotherapeutic drug 5-fluorouracil (5-FU) was explored. Niosome-encapsulated 5-FU was administered to two breast cancer cell lines: (i) the cell line for aggressive breast cancer, that is, triple negative MDA-MB-231 and (ii) the less aggressive ER-positive MCF-7. The idea was to test the efficacy of 5-FU loaded niosomes on a cell with high metastatic potential and another with low metastatic potential. The results indicate a significant cytotoxic effect of 5-FU entrapped in niosomes on both the cell lines at less than half the IC₅₀ value of the bare drug alone.

Alkyl polyglucosides (APG) are biodegradable, non-ionic surfactants from renewable sources with low ecotoxicity. This study developed a novel PEG-free nanoemulsion (NE) using APG to encapsulate Baccharis dracunculifolia essential oil (BDO) for skin repair. Cytotoxicity tests suggested no toxicity for BDO up to 500 μg/mL, and BDO significantly enhanced skin cell migration, indicating potential for skin repair. NEs (1:1 surfactant:BDO) had droplets < 60 nm and low polydispersity (PdI < 0.2). Preliminary NEs had pH > 11, attributed to APG, but adjusting to 6.5 increased droplet size (78 nm) and PdI to 0.3 due to APG interfacial activity changes. After 90 days, NE at pH 6.5 stabilized (~120 nm, PdI < 0.3), indicating a monodisperse system. Conversely, NE at pH 11.5 had a PdI > 0.3 after 21 days, suggesting coalescence. Spectroscopic analyses revealed structural changes in APG and BDO linked to pH variations, supporting the hypothesis of pH-dependent conformational changes in APG. The HET-CAM test indicated a lower irritation score (IS 3.0 ± 0.0) for NE at pH 6.5 vs. 11.5 (IS 3.6 ± 1.15), corroborating the importance of pH adjustment for safe topical applications. This study highlights APG-based NEs as promising for pharmaceuticals and cosmetics, emphasizing the need to further explore APG's pH-sensitive behavior.

CO₂–responsive surfactants are one of the research hotspots in colloid chemistry, and identifying suitable CO₂–responsive surfactants is of significant importance. This study investigates the CO₂–responsive properties of the amino–terminated polyether ZFL–1001 and its potential as a switchable surfactant. The research demonstrates that ZFL–1001 exhibits reversible changes in conductivity, surface tension, viscosity, and emulsion stability when exposed to alternating CO₂ and N₂ conditions. The protonation of secondary amine groups triggered by the introduction of CO₂ enhances hydrophilicity, leading to increased conductivity, reduced surface tension, and the formation of stable micelle networks. These networks significantly influence viscosity and emulsion behavior. Conversely, the removal of CO₂ reverses these effects, returning the system to its initial state. ZFL–1001 also facilitates reversible phase transitions in crude oil emulsions, offering a novel method for emulsion regulation in oil reservoirs. These findings highlight the potential of ZFL–1001 to serve as an environmentally friendly and efficient CO₂–switchable surfactant for applications in smart materials, crude oil extraction, and emulsion control systems.