Search Results (511)

Steady-shear rheology and surface activity of surfactant–polymer solutions were investigated experimentally. Four different polymers were studied as follows: cationic hydroxyethyl cellulose, nonionic hydroxyethyl cellulose, nonionic guar gum, and anionic xanthan gum. The influence of the following four surfactants on each of the polymers was determined: nonionic alcohol ethoxylate, anionic sodium lauryl sulfate, cationic hexadecyltrimethylammonium bromide, and zwitterionic cetyl betaine. The interaction between cationic hydroxyethyl cellulose and anionic sodium lauryl sulfate was extraordinarily strong, resulting in dramatic changes in rheological and surface-active properties. The consistency increased initially, reached a maximum value, and then fell off with the further addition of surfactant. The surface tension of surfactant–polymer solution dropped substantially and exhibited a minimum value. Thus, the surfactant–polymer solutions were much more surface-active compared with pure surfactant solutions. The interaction between anionic xanthan gum and cationic hexadecyltrimethylammonium bromide was also strong, resulting in a substantial decrease in consistency. The surfactant–polymer solution became less surface-active compared with pure surfactant solution due to the migration of surfactant from solution to polymer. The interactions between other polymers and surfactants were weak to moderate, resulting in small to modest changes in rheological and surface-active properties. Surface activity of surfactant–polymer solutions often increased due to the formation of complexes more surface-active than pure surfactant molecules. Full article

The application of lipases in biphasic oil–water emulsions offers an efficient and sustainable alternative to conventional chemical synthesis. However, the natural immiscibility of these phases is a substantial limitation. To address this issue, we proposed a dual-stabilized emulsion system combining a nonionic emulsifier (Kolliphor^® CS 20) and cross-linked polyacrylic acid (Carbopol^® Ultrez 10), exceeding conventional single-stabilized systems. The activity of Candida antarctica lipase B (CALB), both in its free form and immobilized onto an IB-D152 support, was investigated in the prepared emulsion system. The olive oil emulsion stabilized with 10.0% Kolliphor^® CS 20 and 0.1% Carbopol^® Ultrez 10 significantly enhanced the lipolytic activity of immobilized CALB (156.27 ± 3.91 U/g of support), compared to the activity obtained in the emulsion stabilized only with 10.0% Kolliphor^® CS 20 (71.11 ± 3.86 U/g of support). On the other hand, the activity of immobilized CALB in the emulsion containing 5.0% Kolliphor^® CS 20 and 0.1% Carbopol^® Ultrez 10 (62.22 ± 3.85 U/g of support) was lower than in the corresponding system without Carbopol^® Ultrez 10 (72.03 ± 4.63 U/g of support), stabilized with only 5.0% Kolliphor^® CS 20. Furthermore, immobilization onto IB-D152 led to lipase hyperactivation, with activity approximately eight-fold higher than that of free CALB. This dual emulsion stabilization strategy not only improves emulsion stability but also enhances lipase activity, offering new opportunities for scalable, high-performance biocatalysis using emulsions in industrial applications. Full article

The extensive use of submicron emulsion systems, particularly those stabilized by nonionic surfactants, with their proven effectiveness and safety profile, provides a reassuring foundation for our research. Consequently, we designed and engineered new submicron emulsion formulations stabilized with a biocompatible surfactant polyoxyethylated cocoamine, whose nonionic character is due to a high degree of polyoxyethylation. We chose oleic acid as the oil phase, a fatty acid known for its beneficial properties. This led to novel biocompatible nanoemulsions with high stability and cosurfactant-free microemulsions. The dynamic light scattering studies confirmed that both formulations have a nanometric size and low polydispersity index values. Moreover, transmission electron microscopy verified the nanodroplets’ morphological homogeneity and spherical shape. The resulting nanoplatforms can be applied to carry bioactive agents in the pharmaceutical and cosmetic fields. For this reason, we solubilized newly synthesized 5-dimethylamino-5′-nitro-2,2′-bithiophene as a model hydrophobic cargo for delivering poorly water-soluble compounds. This dye was chosen due to its strong solvatochromic behavior and suitability for micropolarity analysis via UV–Vis spectroscopy. We also present a simple method for rapid micropolarity screening to assess the type of nanodispersion via solvatochromic shift as an alternative procedure for evaluating of the oils used to fabricate nanoformulations for pharmaceutical and cosmetic purposes. Full article

This study highlights the use of alkyl polyglucosides (APGs) as sustainable and mild surfactants in cosmetic preparations, such as shampoos, following the principles of green chemistry and environmentally friendly development. APGs are non-ionic surfactants of plant origin. Their favorable dermatological and toxicological profile, as well as their high skin compatibility, make them an excellent alternative to conventional surfactants used in cosmetic products. To increase the sustainability and functionality of cosmetic preparations, the concept of loan extraction was applied, in which the extraction medium is borrowed from the final cosmetic formulation. After the extraction process, the medium enriched with the extracted compounds is returned to the cosmetic. The APGs, as part of cosmetic formulations, were used in the micellar extraction process of grape pomace, a by-product of wine production. The study evaluated the effect of different types of APGs—coco-glucoside and decyl glucoside—and their concentrations on extraction efficiency, measured by LC-MS/MS based on the content of phenolic compounds and amino acids, as well as the total phenolic content, total anthocyanin content and antioxidant activity assessed by UV-Vis spectroscopy. The designed extraction medium was then used to develop a shampoo, which showed a significantly lower zein value compared to the reference preparation without extract, indicating a reduced skin irritation potential. These results highlight the potential of APG in the development of milder, sustainable cosmetic products with the ability to extract bioactive components, supporting their use in the production of environmentally friendly cosmetics. Full article

Surfactants demonstrate considerable potential in enzymatic saccharification at high solids loading (ESHSL). In this paper, the effects of the non-ionic surfactant Tween 80 on enzymatic saccharification of Avicel and steam-exploded poplar (SEP) at high solid loading were studied. The results showed that under the fed-batch conditions of 15.0% solid loading, 20 FPU/g glucan, and 1.0% Tween 80, the maximum enzymatic saccharification rate of Avicel and SEP achieved was 65.4% (128.2 g/L glucose) and 86.4% (93.9 g/L glucose), respectively. Moreover, Tween 80 improved the rheological properties of ESHSL slurry of SEP, especially for the fed-batch model, reducing the complex viscosity, shear stress, and storage modulus. Furthermore, cellulase adsorption assays, SDS-PAGE, Rose Bengal staining, and Zeta potential analysis demonstrated that Tween 80 reduced non-productive adsorption of cellulase (particularly β-glucosidase) on lignin through hydrophobic interactions. All these findings contribute to establishing a foundation for subsequent investigative efforts within the discipline. Full article

Nisin, a food preservative lantibiotic produced by Lactococcus lactis, exhibits potent antimicrobial activity against a wide range of Gram-positive pathogens, including antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). This study explores the development of a novel nano drug delivery platform comprising nisin-loaded niosomes, formulated via microfluidic mixing, and integrated into fast-dissolving oral films for targeted buccal administration. Microfluidic synthesis enabled the precise control of critical parameters including the flow rate ratio, surfactant composition, and lipid concentration, resulting in uniform niosomal vesicles with optimal size distribution (100–200 nm), low polydispersity index, and high encapsulation efficiency. Span 40 and Span 60 were employed as non-ionic surfactants, stabilized with cholesterol to improve bilayer rigidity and drug retention. The encapsulated nisin demonstrated improved physicochemical stability over time and protection against proteolytic degradation, thus preserving its antimicrobial potency. The niosomal suspensions were subsequently incorporated into polymer-based oral films as a final dosage form composed of polyvinyl alcohol (PVA) as the primary film-forming polymer, polyethylene glycol 400 (PEG400) as a plasticizer, and sucralose and mint as a sweetener and flavoring agent, respectively. A disintegrant was added to accelerate film dissolution in the oral cavity, facilitating the rapid release of niosomal nisin. The films were cast and evaluated for thickness uniformity, mechanical properties, disintegration time, surface morphology, and drug content uniformity. The dried films exhibited desirable flexibility, rapid disintegration (<30 s), and consistent distribution of nisin-loaded vesicles. In vitro antimicrobial assays confirmed that the bioactivity of nisin was retained post-formulation, showing effective inhibition zones (16 mm) against Bacillus subtilis. This delivery system offers a promising platform for localized antimicrobial therapy in the oral cavity, potentially aiding in the treatment of dental plaque, oral infections, and periodontal diseases. Overall, the integration of microfluidic-synthesized nisin niosomes into oral films presents a novel, non-invasive strategy for enhancing the stability and therapeutic efficacy of peptide-based drugs in mucosal environments. Physicochemical characterization of the niosomes and niosome films was performed using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to evaluate thermal stability and scanning electron microscopy (SEM) to assess surface morphology. In vitro peptide release studies demonstrated sustained release from both niosomal suspensions and film matrices, and the resulting data were further fitted to established kinetic models to elucidate the underlying drug release mechanisms. This delivery system offers a promising platform for localized antimicrobial therapy in the oral cavity, potentially aiding in the treatment of dental plaque, oral infections, and periodontal diseases. Overall, the integration of microfluidic-synthesized nisin niosomes into oral films presents a novel, non-invasive strategy for enhancing the stability and therapeutic efficacy of peptide-based drugs in mucosal environments. Full article

The effective and rapid separation of oil–water emulsions at room temperature, particularly under harsh environmental conditions like acid–base fluctuations, high salinity, and the coexistence of surfactants, remains a significant challenge in oily wastewater treatment. To address this, a novel amphiphilic demulsifier, MOF-74@SiO₂-GPTMS grafted ANP (MSG-ANP), was synthesized by first modifying MOF-74@SiO₂ (MS) with γ-glycidoxypropyltrimethoxysilane (GPTMS) to create epoxy-functionalized MSG particles, followed by grafting the non-ionic polyether C₁₂–C₁₄ aliphatic polyethylene oxide polyoxypropylene (ANP) onto MSG. Bottle tests demonstrated that MSG-ANP achieved a high demulsification efficiency of 93% within 15 min for oil-in-water emulsions at room temperature. It exhibited excellent environmental tolerance, maintaining efficiencies of 89% at pH 3.0, 82% at pH 11.0, and 95% under high salinity (50,000 mg/L, pH 6.8). Furthermore, MSG-ANP effectively treated surfactant-stabilized emulsions, exceeding 96% efficiency against both cetyltrimethylammonium bromide and sodium dodecyl sulfate after 30 min, outperforming commercial demulsifiers SP-169 and AR-331 by factors of 1.2 and 1.6, respectively. This superior performance stems from synergistic hydrogen bonding (via hydroxyl, ether, ester, Fe-O, and Si-O groups) destabilizing the interfacial film and electrostatic neutralization of coalescing charged droplets. Consequently, MSG-ANP presents a promising solution for rapid, room-temperature demulsification across a wide pH range and under high-salinity conditions. Full article

This study systematically analyzes the influencing factors and optimization strategies of foam stability and performance for CO₂-soluble foaming agents in high-temperature and high-pressure (HTHP) complex reservoir environments. By constructing a HTHP experimental system and utilizing dynamic foam testing, interfacial tension analysis, and microscopic observation of liquid films, the effects of chemical factors (e.g., pH, foaming agent concentration, stabilizer synergy) and physical factors (e.g., temperature, pressure) on foam behavior are investigated. The results show that the nonionic surfactant E-1312 exhibits optimal foam performance in neutral to mildly alkaline environments. The foam performance tends to saturate at around 0.5% concentration. High pressure enhances the foam stability, whereas elevated temperature significantly reduces the foam lifetime. Moreover, the addition of nano-sized foam stabilizers such as silica (SiO₂) can significantly delay liquid film drainage and strengthen interfacial mechanical properties, thereby improving foam durability. This study further reveals the key mechanisms of CO₂-soluble foaming agents in terms of interfacial behavior, liquid film evolution, and foam formation in porous media, providing theoretical guidance and optimization pathways for the molecular design and field application of CO₂ foam flooding technology. Full article

Surfactant-enhanced remediation is a promising approach for treating petroleum-contaminated soils, particularly in areas where conventional methods are limited by environmental constraints. This study investigates the application of Tween 80, a non-ionic surfactant, for remediating diesel-contaminated Albic Podzolic soils typical of boreal regions. Laboratory experiments were conducted over 90 days, using two surfactant concentrations (3.0 × 10⁻⁴ and 1.5 × 10⁻⁴ mol L⁻¹) and two temperature regimes (22–24 °C and 2–3 °C), simulating seasonal variability in cold-climate contaminated sites. The lower Tween 80 concentration—below the critical micelle concentration—proved more effective, achieving up to 21% total petroleum hydrocarbon (TPH) reduction at ambient temperature and 17% under refrigerated conditions. Treated soils also exhibited pH neutralization, indicating improved chemical stability. Acute toxicity bioassays (Vibrio fischeri and Ceriodaphnia affinis) confirmed the environmental safety of the applied concentrations (≤0.3 mol L⁻¹). These results support the practical use of Tween 80 in the remediation of petroleum-contaminated soils under boreal constraints, providing transferable data for designing safe and efficient field-scale treatment strategies. This work also offers insights that are relevant to remediation policies in cold climates and to the adaptation of surfactant-assisted technologies for diverse field conditions. Full article

Collagenases are enzymes with broad biotechnological applications in medicine. This study describes the production and characterization of a collagenase from Aspergillus serratalhadensis URM 7866, isolated from the Caatinga biome. Solid-state fermentations were conducted using wheat bran under varying conditions of pH (6, 7, 8), moisture content (50%, 60%, 70%), and substrate concentration (2.5 g, 5 g, 10 g). The optimal condition—10 g of wheat bran at pH 8 and 70% moisture—yielded the highest collagenolytic activity (177.96 U/mL) and a specific activity of 50.55 U/mg. The enzyme was purified via multiple chromatography, with pre-purification and final purification factors of 18.09 and 20.21, respectively, reaching a specific activity of 1021.86 U/mg. The enzyme showed optimal activity at 50 °C and pH 8, with stability from 20 to 40 °C and pH 7–9. PMSF caused >80% inhibition; EDTA caused ~34% inhibition. Activity increased with Na⁺ and Ca²⁺ and was inhibited by Zn²⁺. The enzyme retained full activity in anionic and non-ionic surfactants (1–10%). FTIR confirmed characteristic amide bands, and kinetic analysis revealed a Km of 1.72 mg/mL and Vmax of 6.89 mg/mL/min. These findings support its potential for alkaline and surfactant-rich industrial processes. Full article

This study examines the effects of several commercial surfactants on the dispersion of catalyst inks for proton exchange membrane fuel cells (PEMFCs). Catalyst inks containing Pt/C were spray-coated and assembled into membrane electrode assemblies (MEAs) by hot pressing. The structural and electrochemical properties of the resulting catalyst layers were characterized through particle size analysis, zeta potential measurements, contact angle determinations, and single-cell performance tests. Among the formulations evaluated, the ink with non-ionic surfactant Triton X-100 (TX) delivered the best performance, achieving a current density of 1134 mA/cm² at 0.3 V—substantially higher than that of the surfactant-free control. These findings provide practical guidance for selecting appropriate surfactants to optimize catalyst-ink preparation and enhance PEMFC performance. Full article

In this research work, the electrochemical evaluation of a non-ionic gemini surfactant as a green corrosion inhibitor for X100 pipeline steel in CO₂-saturated brine solution was carried out by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PPC). The corrosion inhibition performance of the gemini surfactant was studied in static and hydrodynamic conditions at room temperature and 60 °C. Electrochemical measurements showed that the inhibitor’s performance was enhanced with increasing inhibitor concentration and with increasing exposure time at room temperature, reaching the highest inhibition efficiency (η) at 100 ppm. With increasing temperature, the inhibitor efficiency decreased, with similar behavior at all concentrations. The analysis of the cathodic polarization curves at different rotation speeds showed the strong influence of mass transport on the cathodic process in the absence and the presence of the inhibitor. Under hydrodynamic conditions, PPC and EIS results indicated that the best inhibitor performance was with a concentration of 50 ppm, achieving a maximum inhibition efficiency of 91%. The adsorption of the inhibitor molecules on the surface obeyed the Langmuir isotherm, and the type of adsorption was mixed in all the study conditions. Surface characterization by scanning electron microscopy (SEM) revealed the formation of a protective corrosion inhibitor film. Full article

The widespread use of non-ionic surfactants, e.g., nonylphenol ethoxylates or dodecyl ethoxylates, may result in their occurrence in foodstuffs. In this paper, extracts from the coatings and from the contents of high-barrier food pouches were analyzed by high-pressure liquid chromatography–mass spectrometry. These flexible pouches are an alternative package format of growing interest which can replace traditional cans. In almost all samples, nonylphenol ethoxylates and dodecyl ethoxylates were detected. The identified nonylphenol ethoxylates usually contained 4–10 oxyethylene units, while the identified dodecyl ethoxylates contained 3–13 oxyethylene units. However, in a few samples, longer fractions of dodecyl ethoxylates were detected, namely those containing >15 oxyethylene units. A comparison of the non-ionic surfactant concentrations in the coating extracts with their concentrations in the content extracts indicated that the coating materials were not the main sources of the contents’ contamination. Other contaminants, namely BADGE conjugates and cyclic cooligoesters, which are common contaminants of canned foodstuffs, were found to rarely occur in high-barrier food pouches. Unexpectedly, in one sample polypropylene glycol was detected at a low concentration; this compound has not been previously identified as a potential food contaminant. Full article

Novel infection control practices are necessary to reduce the incidence of healthcare-associated infections (HAIs). Since 2007, probiotic-based cleaning solutions have been proposed as an alternative to traditional methods using disinfectants and detergents in healthcare settings, including hospitals. We conducted a comprehensive search across Google Scholar, PubMed, Scopus, and Web of Science resources. Studies that assessed the reduction in pathogens on surfaces and the emergence of HAIs after the use of probiotic-based cleaning solutions were eligible for evaluation. A total of 16 studies (13 in clinical settings and 3 on experimental surfaces) were included. The Staphylococcus species were most commonly identified before and after the use of probiotic-based cleaning solutions. All studies showed numerically lower pathogen counts and fewer HAIs after using probiotic-based cleaning solutions compared to disinfectants and detergents. Three studies indicated a reduction in antimicrobial resistance genes after use of probiotic-based cleaning solutions. One of these showed statistically significant differences compared to traditional disinfectants (alcohol, amines, and quaternary ammonium compounds) and detergents (non-ionic and anionic surfactants). The results of the included studies suggest the consideration of probiotic-based cleaning solutions for infection control in healthcare systems. However, given the novelty of this approach, further studies are needed to verify the evaluated findings and investigate the short- and long-term effectiveness, and safety of probiotic-based cleaning solutions on infection control practices in healthcare settings. Full article

A novel centrifuge-less cloud point extraction (CL-CPE) method was developed for the spectrophotometric determination of copper(II) using 4-nitrocatechol (4NC) as the chelating agent. The extraction system utilizes a mixed micellar phase composed of the nonionic surfactant Triton X-114 and the ionic liquid (IL) Aliquat^® 336 (A336). The extracted ternary ion-association complex, identified as (A336⁺)₂[Cu(4NC)₂], exhibits a maximum absorbance at 451 nm, with a molar absorption coefficient of 8.9 × 10⁴ M⁻¹ cm⁻¹ and a Sandell’s sensitivity of 0.71 ng cm⁻². The method demonstrates a linear response in the copper(II) concentration range of 32–763 ng mL⁻¹ and a limit of detection of 9.7 ng mL⁻¹. The logarithmic extraction constant (log K_ex) was determined to be 7.9, indicating efficient extraction. Method performance, evaluated by the Blue Applicability Grade Index (BAGI) and the Click Analytical Chemistry Index (CACI), confirmed its feasibility, practicality, simplicity, convenience, cost-effectiveness, environmental friendliness, and analytical competitiveness. The proposed IL-CL-CPE method was successfully applied to the analysis of a dietary supplement, a solution for infusion, and synthetic mixtures simulating various copper alloys. Full article