Journal of Surfactants and Detergents最新文献

The release of hydrocarbons (HC) into the marine environment has serious consequences, both economically and ecologically. This work presents an efficient process to remove HC pollution from seawater: cloud point extraction (CPE), considered to be a reliable, inexpensive, and environmentally friendly method, using the readily biodegradable nonionic surfactants Lutensol ON30 and Tergitol 15-S-7. A real salt water sample with a high chemical oxygen demand (COD = 1700 mg O₂/L) was thus treated. First, the phase diagrams of the binary systems (water–surfactant), and the pseudo-binary systems (water–surfactant–HC), were determined. Second, after a 24 h settling time, considered as optimal, the extraction results, that is, residual soluble COD, residual percentage of surfactant in the dilute phase and volume fraction of coacervate at equilibrium, were expressed in terms of temperature and initial surfactant concentration. For each parameter, the results obtained were modeled using the response surface methodology and represented on three-dimensional diagrams. They show that the COD can be reduced to 10 and 15 mg O₂/L, using Lutensol ON30 and Tergitol 15-S-7, respectively, under seawater temperature conditions. Finally, it was shown that the surfactant can be recycled. The present work demonstrates that CPE can reduce the HC content of seawater on a laboratory scale.

Increased demand and sustainability concerns for palm derivatives, which include the major plant-based feedstocks for surfactants in household, personal care, and industrial & institutional (I&I) applications, is anticipated to cause supply concerns over the next decade. This article reviews the impact of the fatty acid alkyl chain length and unsaturation and resulting physical properties from non-palm feedstocks on formulation, processing, and functionality. Potential adjustments and their limitations are also discussed.

The quality and safety of dairy products are highly valued by consumers and dairy manufacturers, which is mainly ensured by thorough cleaning of dairy production equipment. Milk fouling can cause pipes to clog and reduce transmission. Incomplete cleaning can cause microbial breeding, which will affect the quality and safety of dairy products. To achieve efficient and rapid cleaning of dairy processing equipment, cleaning agents have always been a necessary choice for dairy and food enterprises. This paper describes the production mechanism of milk fouling, the cleaning mechanism by cleaning agents, and the cleaning process. Development of cleaning agents are introduced in detail, include compound alkaline/acid/neutral cleaning agents, enzyme cleaning agents and cleaning additives. The factors affecting cleaning efficiency are also viewed, which include type and dosage of cleaning agents, cleaning process (cleaning time, cleaning liquid temperature, cleaning fluid flow rate), and other influencing factors (cleaning fluid pressure, Reynolds number and shear stress, surface types). Four aspects are reviewed in this manuscript, include cleaning objects (milk fouling), cleaning substances (cleaning agents), how to clean (cleaning mechanism) and how to clean efficiently (cleaning influencing factors), which provides a valuable reference for the improvement of the dairy cleaning process.

CO₂-in-water (C/W) foams have attracted much attention given their eco-friendliness in recent years. However, limited surfactants were able to effectively adsorb at the supercritical CO₂–water (C–W) interface considering the weak solvent strength of CO₂, especially at high temperatures. Herein, attempts have been made to design suitable CO₂ foaming agents by evaluating the influence of proportions of anionic and cationic surfactants and the affinity between aminopropyl methyl siloxane (APSi) and CO₂. Through systematical foamability and foam stability experiments, together with the measurements of C–W equilibrium and dynamic interfacial tensions, the adsorption and stabilization mechanisms of sodium alpha olefin sulfonate (AOS)-APSi aqueous dispersions on the CO₂ foam films are revealed. Excellent foam properties were observed at AOS/APSi mass ratio of 9:1, in which initial foam height (h₀) and half-life period (t_1/2) first increased and then decreased with increasing pressure, whereas the interfacial tension decreased with increasing pressure. The results indicate that the interaction of anionic and cationic head-groups contributes to accelerating the surfactant adsorption rate from bulk to the C–W interface, enhancing foamability and stabilizing foam. Besides, the AOS/APSi mass ratio of 8:2 shows a good affinity for CO₂ at 15 MPa, of which h₀ is 26% higher and t_1/2 is 60% slower than AOS alone. Furthermore, the initial mean bubble area of both 9:1 and 8:2 AOS/APSi mixtures was around half that of AOS alone. This work broadens the design of novel surfactant methodologies including CO₂ foam, providing a theoretical guidance for the application of CO₂ on enhanced-oil-recovery technologies.

The glycolipids cellobiose lipids (CL) and mannosylerythritol lipids (MEL) are biosurfactants mainly synthesized by microorganisms of the Ustilaginaceae family. They have a large structural diversity, varying in their sugar moieties and the attached fatty acids, resulting in a prospectively broad range of applications. This literature review provides a detailed overview of known microbial producers of CL and MEL, and their respective metabolic pathways that result in different molecular structures. Further, current advances in the aerobic fermentative synthesis of the glycolipids and their purification methods are illustrated. All influencing factors identified to date with regard to the fermentation are highlighted in detail: For CL synthesis usually hydrophilic carbon sources are used as substrate, whereas hydrophobic carbon sources are usually metabolized to MEL. Nitrogen limitation was described as a major trigger for glycolipid synthesis and an acidic pH range was favored for increased CL production. An overview of applied fermentation parameters in recent publications (e.g., substrate-concentrations, feeding approaches) demonstrates the future potential of CL and MEL production optimization. Foaming during fermentation is either combated or exploited by foam fractionation as the first purification step. The current purification processes focus on solvent extractions and chromatography in the laboratory scale and a need for development was identified for future scale-up. Finally, environmental hotspots during CL and MEL production are presented and future optimization potentials are highlighted.

Conventional detergent formulations contain either petroleum-derived or synthetic chemicals. Hence, the replacement of these chemicals with natural products such as enzymes is considered a green technology. Among these enzymes, protease is renowned in detergent formulations. Therefore, the objective of this study was to explore and characterize a new protease from Phytolacca dodecandra, because the plant is traditionally known for detergency purposes. Enzyme extraction was performed with Glycine/NaOH buffer, pH = 10.0. Gelatin hydrolysis and agar well diffusion tests were implemented as qualitative assays, whereas the enzyme assay technique was applied for the quantitative investigation of the new protease from plant extracts. The crude enzyme was partially characterized concerning temperature and pH tolerance, washing performance, detergent compatibility, and stability. The finding of this study revealed that Phytolacca dodecandra contains protease and is characterized by 1418.84 U/mL of enzyme activity, where 1 unit (U) of enzyme activity refers to the amount of enzyme required to liberate 1 μg of tyrosine/mL/min under the defined assay conditions. The enzyme showed maximum activity at pH 10.5 and 45°C. The enzyme was stable and maintained 99.52% activity at 40°C and 91.73% at pH 10.0 after 2 h pre-incubation. The enzyme showed excellent wash performance and could potentially remove blood stains completely within 3 min. After 2 h of pre-incubation the enzyme maintained 69.06% and 54.88% of its activity in the presence of Azzy and Sunlight, respectively. The enzyme maintained 71.99% of its residual activity after 60 days of storage. If further studies are conducted, all these properties of the newly investigated protease can make the enzyme applicable in detergent formulations.

Biosurfactants represent a promising choice for the development of environmentally friendly and gentle personal care cleansers. Building viscosity is one of the major challenges to apply biosurfactants. In this study, sodium lauroyl sarcosinate (LS) and sodium lauroamphoacetate (LA) were used as bases to build wormlike micelles, and subsequently rhamnolipids were introduced to build mild surfactant systems. The LS-LA mixture had the highest viscosity at the mass ratio of 1:5 and pH 6.0. After adding 1 wt% and less rhamnolipid, relatively high viscosity can be maintained. The viscosity of LS-LA-rhamnolipid can be increased by adding NaCl and more significantly by the addition of carrageenan due to its synergistic interactions with the surfactant mixture. In addition, the foaming properties of the systems are characterized with different amounts of rhamnolipid and carrageenan, which are correlated with the bulk viscosity and interfacial elasticity of the diluted solution used for the foaming test. Rhamnolipids have both high mildness and cleaning efficacy and adding rhamnolipids can significantly increase the mildness of the system. This study offers practical solutions for the incorporation of rhamnolipids or other biosurfactants in the formulation of personal care cleansers.