Journal of Surfactants and Detergents最新文献

In this study, a novel high-temperature and high-pressure foam evaluator with variable diameters inner cell and cylinder flip function was designed on our own, which can solve the problems such as difficulties in foam generation and inaccurate determination of various foam parameters by the same type of instruments, through which the foaming performance of more than 10 betaine surfactants was evaluated. The results show that: (1) the higher the pressure, the higher the foaming rate of the foaming agent and the more stable the foam, but the foam stability of the foamers at low and high pressures, and low and high temperatures do not correspond exactly, and the foaming agent used needs to be screened under simulated reservoir conditions. (2) The comprehensive foaming performance of different types of foamers with different molecular structures found that hydroxy sulfobetaine with longer carbon chains has a relatively better foaming performance. Therefore, for the reservoir conditions of temperature 130°C, pressure 30 MPa, and salinity 22 × 10⁴ mg/L, hydroxy sulfobetaine, which does not contain an amide group in the molecule, can be considered preferentially as a foaming agent. The results can guide the selection of foaming agents for high-temperature and high-salinity reservoirs.

Present study concerned with expression and biochemical characterization of lipase enzyme for potential use in detergent formulation. Lipase gene (1242 bp) of Bacillus thuringensis was cloned and expressed in Escherichia coli BL21 strain using pET-21a(+) expression vector. Maximum expression of cloned lipase gene was obtained at 37°C with an induction of 0.4 mM IPTG (Isopropyl ß-D-1-thiogalactopyranoside) after 4 h of induction. Recombinant lipase was purified to homogeneity using immobilized metal ion affinity chromatography carrying 109.80 U/mg specific activity with 38.79 purification folds. Molecular mass of purified lipase was determined as 45 kDa using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified recombinant lipase showed stability up to 90°C and retained significant activity (52%) after 4 h at 90°C. It was also found to be stable at a wide range of pH and in the presence of higher concentrations of several inhibitors (sodium dodecyl sulfate, dimethylsulfoxide, sodium azide, β-mercaptoethanol, polysorbate 80, dithiothreitol) as well as organic solvents (acetone, methanol, ethanol, isopropanol, n-butanol). The activity of recombinant lipase was enhanced in the presence of various metal ions and activated up to 200% by Ca²⁺. The compatibility of recombinant lipase with commercial detergents and other additives as well as its broad substrate specificity endorse the potential application of this enzyme in detergent formulations.

Enhancing oil recovery through surfactants has proven to be a successful strategy in recent times. However, traditional surfactants have their limitations, particularly in terms of stability under high temperatures and salinity levels. This study delved into a groundbreaking macromolecular polymeric surfactant, S-AV, which holds the unique ability to transform rock surface characteristics, effectively stripping away residual oil while maintaining resilience against elevated temperatures and salinity. S-AV was synthesized through a free-radical copolymerization process, incorporating benzyl, perfluoroalkyl, alkyl-, benzyl-, ethylene glycol, and amide-alkyl-sulfonate groups, ultimately yielding a comb-like molecular structure. S-AV demonstrated exceptional prowess, swiftly reducing the underwater oil contact angle to 53.4° in just 48 h. This synthesized surfactant also retained its phase stability up to salinity levels of 36,000 ppm, with temperature having no disruptive impact on its phase stability performance. Furthermore, S-AV showcased remarkable viscosity reduction in conditions of high temperature and salinity. The core flooding experiments underscored the potential of S-AV, as its injection led to a significant oil recovery rate of up to 83%. These findings position S-AV as a promising candidate for practical enhanced oil recovery applications.

Nanoemulsions exhibit a wide range of practical applications owing to their smaller particle size, stability, and enhanced bioavailability. Conventional surfactants widely used in nanoemulsion formulations namely, polysorbate 80, macrogolglycerol ricinoleate, and 4-octylphenol polyethoxylate have been associated with anaphylactoid responses, alterations in normal flora, cytotoxicity and tissue damage. The use of less toxic, environment-friendly microbial biosurfactants in the formulation of nanoemulsions have been demonstrated to manifest stability, slow drug release, enhanced skin permeability, and bioactivity. The type and composition of mixed microbial biosurfactants used in nanoemulsions can decrease the droplet size and synergistically increase the stability. Moreover, a lower concentration of drug-loaded surfactin-based nanoemulsion synergistically inhibited the proliferation of cancer cells by 50% (IC50). The scope of the current review is to focus on the prospect of substituting conventional surfactants with biosurfactants obtained from microbial origin for nanoemulsion formulations. It also aims to draw attention to the paucity of research in the combinatorial study of biosurfactants and functional drugs used in nanoemulsions. The review emphasizes the bioactivity of microbial biosurfactant-based nanoemulsions and their applications in diverse sectors. The differences in emulsion stability and size of microbial biosurfactant and conventional surfactant-based nanoemulsions have been highlighted. The study intends to promote comparative research between nanoemulsions prepared using conventional surfactants and microbial biosurfactants.

Photosensitive micellar solutions of mixed surfactants and photosensitive additives have gained much interest. However, there are no reports on photosensitive micellar solutions containing trimeric cationic surfactant. In the study, novel photosensitive viscoelastic micellar solutions consisting of trimeric cationic surfactant (TEC) and trans-ortho-methoxycinnamic acid (trans-OMCA) were investigated. This study utilized rheology, UV–vis spectroscopy, and cryo-TEM to investigate the photo-responsive behavior and mechanism of the TEC/trans-OMCA micellar solutions. Rheological studies revealed that the concentration of TEC and trans-OMCA, as well as temperature, significantly affected the viscoelastic properties of the micellar solutions. Furthermore, the Carreau and Maxwell models might be used to characterize the flow curves and viscoelasticity of the micellar solutions, respectively. Notably, TEC/trans-OMCA micellar solutions exhibited excellent light-induced thinning characteristic, with the optimal performance at a mass ratio of φ = 0.5. After UV irradiation, the zero-shear viscosity of TEC/trans-OMCA (0.6/0.3 wt%) micellar solution was reduced by 352 times, while the viscoelasticity and the area of hysteresis loops were significantly reduced. This drastic change in the rheological characteristics of the micellar solutions could be attributed to the photoisomerization of trans-OMCA and the resulting changes in the internal microstructure of the solutions. Moreover, the viscosity of the micellar solutions diminished as the temperature increased, with the remaining viscosity of the TEC/trans-OMCA (1.0/0.5 wt%) micellar solution at 36.4 mPa s at 95°C. This study expands on the potential utilization of oligomeric surfactants in the construction of photorheological viscoelastic fluids.

This study investigates the adsorption behaviors of surfactants in sandstone reservoir rocks containing various amounts of carbonate cement/minerals and their impact on wettability alteration under low-salinity conditions. Two types of rock samples from sandstone reservoirs of Assam oilfields in India are selected based on XRD results. These rock types are (i) high carbonate cement (HCC) core sample with higher carbonate cement (calcite 5.6% and dolomite 4.0%), and (ii) low carbonate cement (LCC) core sample with lower carbonate cement (calcite = 0.5% and dolomite 0%). The study reveals that the mineralogy of sandstone reservoir rocks especially the carbonate minerals affects the brine-rock interactions including wettability alternation and surfactant adsorption. Notable differences (2° to 8°) in contact angles for the two rock types at different salinities revealed that carbonate cement in sandstone thus impacts brine-rock interactions. Further, low salinity surfactant (LSS) could positively alter the wettability of both rock types to water-wet conditions (contact angle <60°). The most favorable wettability alterations (up to 30°) were achieved with cationic LSS solutions for both core types. Using LSS solutions also reduced the adsorption of anionic surfactant by around 40% and 33% for HCC and LCC rock samples, respectively. The study's novelty emanates from investigating the impact of sandstone reservoir rock mineralogy with varying amounts of carbonate cements on the adsorption behavior of surfactants under low-salinity conditions. Moreover, this study provides a better understanding of the interrelationship existing between the degree of wettability alteration and the amount of surfactant adsorbed by sandstone rocks.

The reduction in friction is a desired property in many industries. Some of the applications include the movement of liquid or slurry through a pipeline in oil or mining, the grinding of one metal on another during fabrication, metal on paper in the making of nearly any paper product, to even something closer to home with the movement of a brush or comb through one's hair. Friction yields higher degrees of strain or stress on one or both of the substrates. This can be costly due to energy requirements, wear of equipment, or even breakage of the substrate. Even though the need exists in so many industries, the mechanisms of lubricity vary enough in each that there really is not a universal lubricity aid that can successfully be applied across the different industries. A family of novel lubricity aids based on alkyl polyglucosides have been synthesized and evaluated in the lab on both metal/metal friction reduction as well as comb/hair friction reduction. One of the modified alkyl polyglucosides has yielded excellent reduction in friction in both applications.

Mannosylerythritol lipid (MEL) is a microbial surface-active glycolipid biosurfactant produced by numerous microorganisms. MEL is produced as a major product by Pseudozyma sp. and as a minor product by Ustilago sp. MEL has recently received much practical attention due to its structural diversity, broad biochemical functions, and biocompatibility with the environment. In this review, the production of MEL from various feedstocks, and antimicrobial and antiadhesive properties are discussed. Furthermore, the applications of MEL as an antimicrobial agent in food, moisturizer in cosmetics, as an apoptotic agent in pharmaceuticals, and as a wetting agent in agriculture applications are highlighted. Finally, an overview of MEL production from waste materials presents huge potential for increasing the necessary change to a circular economy.

This research highlights the efficacy of mixed micellar systems as an innovative chemical formulation for improving the binding properties of active pharmaceutical drugs. The formulations based on the mole fraction were utilized for preparing mixed micelles with anionic sodium dioctyl sulfosuccinate (AOT) and sodium dodecyl sulphate (SDS). DLS measurements demonstrated the formation of small micelles and mixed micelles in SDS-AOT combinations. A UV absorbance investigation demonstrated the effectiveness of the SDS-AOT mixed micelles for determining the binding constant (K_b) and mean ion occupancy (i₀) of the anticonvulsant gabapentin (GBP) drug. K_b values increased, but the occupancy (i) of GBP per micelle decreased by decreasing the mole fraction (α) of SDS from α_SDS 0.9 to 0.1, predicting a shift in occupancy of drugs from the Palisade to the Stern layer. To get a better comprehension of micellization behavior and preferential interaction of the drugs under study, molecular docking studies were performed. According to the docking studies, the GBP displayed significant binding in the presence of SDS-AOT when compared to pure SDS and AOT molecules. Ultimately, in pharmaceutical applications, mixed micelle played an important role in enhancing the binding and encapsulation efficiency of drugs.

The utilization of natural clay minerals for the adsorption of endocrine-disrupting chemicals (EDCs) presents a cost-effective and environmentally friendly approach. However, the hydrophilic nature of clay minerals' surface limits their efficacy in removing these hydrophobic pollutants. To overcome these limitations, this study employed two cationic surfactants, cetylpyridinium chloride (CPC) and cetyltrimethylammonium chloride (CTAC), to modify kaolin minerals to enhance their capacity to adsorb a specific type of EDCs, bisphenol A (BPA), and its analogs. The experimental results validated that the surfactant-modified kaolin exhibited remarkable efficiency in removing BPA from water. The equilibrium adsorption capacities of CPC-K and CTAC-K for BPA were determined to be 11.4 mg/g (pH = 2.0–8.0) and 13.4 mg/g (pH = 2.0–6.5), respectively. Kinetic analysis revealed that the BPA adsorption followed a pseudo-second-order kinetic process, while isotherm analysis suggested that the BPA adsorption was better described by the Freundlich model (R² = 0.993–0.998). The surfactant-modified kaolin demonstrated a retention of over 70% of its initial adsorption capacity after five cycles of desorption and regeneration, further confirming its potential for recycling. Additionally, these modified adsorbents exhibited excellent compatibility in removing bisphenol analogs. These findings provide valuable insights into the practical application of surfactant-modified clay minerals for the elimination of hydrophobic organic pollutants from water.