Journal of Surfactants and Detergents最新文献

Aqueous two-phase systems (ATPS) were used to evaluate the in situ production and separation of lipopeptides produced by Bacillus amyloliquefaciens. This method demonstrates the first step towards continuous production of lipopeptides. Growth and lipopeptide production were evaluated at elevated trisodium citrate, sodium potassium tartrate, dipotassium hydrogen phosphate, and sodium sulphate concentrations (from 0.2 to 0.8 M). Citrate concentrations negatively impacted growth, while phosphate, sulphate, and tartrate showed little effect, with cultures reaching a maximum cell dry weight between 3.98 and 4.5 g L⁻¹, in line with the 4.5 g L⁻¹ observed with standard media optimized for lipopeptide production. These results were coupled with the production of 137 mg L⁻¹ lipopeptides at 0.8 M tartrate, 95 mg L⁻¹ at 0.8 M phosphate, and 14 mg L⁻¹ at 0.8 M sulphate. Two-phase forming systems were tested, with the addition of various concentrations of PEG 8000, excluding citrate. In the phosphate ATPS, iturin partitioned primarily to the polymer phase with concentrations up to 267 mg L⁻¹, while the fengycin primarily partitioned to the salt phase with concentrations of 118 mg L⁻¹. Surfactin was found to accumulate in the solid phase under ATPS conditions. This method is simple, scalable, and novel.

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.

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.

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.

CO₂ foam system has the functions of oil displacement, plugging, and fracturing, and plays an important role in improving oil and gas production. In this paper, the effectiveness and mechanism of different surfactant systems for CO₂ foam and the methods to stabilize CO₂ foam are reviewed. The effectiveness and mechanism of ionic, nonionic, and Gemini surfactant systems for CO₂ foam were analyzed. The research status of CO₂ foaming agent system, gas-soluble CO₂ foaming agent system, and CO₂ intelligent response foaming agent system based on anionic, nonionic, and zwitterionic compounds was described. The mechanism of polymer and nanoparticles stabilizing CO₂ foam system was also discussed. Through investigation, it is found that the performance of CO₂ foam system compounded with various chemicals is better, and the research is relatively perfect and diversified, so we can pay attention to the refinement of the compounding process in the future. Sulfonation and modification of surfactants can further improve the properties of surfactants. The characteristics of Gemini surfactants, supercritical CO₂, and CO₂-sensitive surfactants can be used to make CO₂ foaming agent have the characteristics of easy recovery, sustainability, anti-corrosion, on–off control, and fluidity control. There is still room for development of such surfactants. Using polymers and nanoparticles to stabilize foam is the future development trend. This paper provides guidance for the further development and field application of highly effective CO₂ surfactant.

The solidified foam extinguishing agent was prepared by using the mixture of sodium dodecyl sulfate and sodium alcohol ether sulphate as surfactant, xanthan gum as foam stabilizer, aluminum sulfate as coagulant and three kinds of cement powder. The effect of cement type on the physicochemical properties and thermal insulation properties of solidified foams were investigated. The results show that the aluminate cement solidified foam (SF_AC) exhibits the optimal comprehensive performance with the collapse ratio of 5.68%, and the excellent adhesion and thermal insulation simultaneously. The aluminate cement rapidly hydrates and condenses in the process of mixing with the foam fluid to form a stable three-dimensional skeleton system connected by numerous cell structures. The SF_AC shows the highest viscosity of 6635 ± 3 mPa s and the shortest initial setting time of 185 ± 3 s among three samples, which maintains the surface integrity and the stability under high thermal radiation, thus effectively slowing down the heat transfer inside the solidified foam.

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.