The present study used calorimetric techniques to follow the interaction of random and block ethylene oxide (EO)-propylene oxide (PO) copolymers with ionic surfactants. Features such as the intensity of the interaction (evaluated through their critical aggregation concentrations) and the profile of the isothermal titration calorimetry (ITC) curves were comparatively analyzed for random and block copolymers with similar composition (number of EO and PO units). Random copolymers displayed an interaction similar to that observed with other hydrophilic homopolymers with the additional characteristic that the intensity of the interaction increased with the increase in the copolymer hydrophobicity (as determined by its PO content), revealing that these copolymers display an intermediate behavior between PEO and PPO. For nonaggregated block copolymers (unimers) with large enough EO blocks (molar mass above 2000 g mol-1), ITC curves revealed that the anionic surfactant sodium dodecylsulfate (SDS) interacts with the PO and EO blocks almost independently, being more favorable with the PO block, which controls the critical aggregation concentration (cac) value. Effects of temperature and of the nature of the ionic surfactants on their interaction with these copolymers were found to agree with the previously reported trends.
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http://dx.doi.org/10.1021/jp0761362 | DOI Listing |
Langmuir
January 2025
Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States.
Modification of silica interfaces by covalent attachment of functional ligands is a primary means of controlling the interfacial chemistry of porous silicas used in separations, environmental cleanup, and biosensing. Recently, modification of hydrophobic, -alkyl-silane-functionalized interfaces has been achieved through self-assembly of zwitterionic phospholipids or mixed-charged surfactants to form "hybrid bilayers", producing interfaces that mimic lipid-bilayer partitioning and provide shape-selective partitioning of aromatic hydrocarbons. Charged headgroups, however, introduce electrostatic interactions that strongly influence the retention of ionizable solutes and require careful control over pH and ionic strength in the solution phase.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Chemistry & Environmental Engineering, Yangtze University, Jingzhou 434023, PR China.
Substantial amounts of oily wastewater are inevitably generated during petroleum extraction and petrochemical production, and the effective treatment of these O/W emulsions is crucial for environmental protection and resource recovery. The development of an environmentally friendly, cost-effective, and efficient demulsifier that operates effectively at low concentrations remains a significant challenge. This study introduces an eco-friendly ionic liquid demulsifier, Cotton Cellulose-Dodecylamine (CCDA), which demonstrates exceptional demulsification performance at low concentrations.
View Article and Find Full Text PDFEnviron Technol
January 2025
Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
The remediation of oil-contaminated soil poses significant environmental challenges, often necessitating innovative approaches for effective and sustainable solutions. This study focuses on the synthesis, characterisation, and application of biodegradable capsules loaded with surfactant for enhanced oil remediation of a clean sand. By controlling the release properties of capsules, the research aims to overcome the limitations of conventional surfactant-based remediation methods, such as rapid washout and reduced efficacy over time.
View Article and Find Full Text PDFRSC Adv
January 2025
The Center for Chemical Biology, School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan +81-45-566-1580 +81-45-566-1839.
We prepared a cellulose nanofiber (CNF)-based porous membrane with three dimensional cellular structures. CNF was concentrated a surfactant-induced assembly by mixing CNF with a cationic surfactant, domiphen bromide (DB). Furthermore, they were accumulated by centrifugation to obtain a CNF-DB sol.
View Article and Find Full Text PDFPeerJ
January 2025
Faculty of Agricultural Sciences, University of the Punjab, Lahore, Punjab, Pakistan.
The continuous contamination of heavy metals (HMs) in our ecosystem due to industrialization, urbanization and other anthropogenic activities has become a serious environmental constraint to successful crop production. Lead (Pb) toxicity causes ionic, oxidative and osmotic injuries which induce various morphological, physiological, metabolic and molecular abnormalities in plants. Polyethylene glycol (PEG) is widely used to elucidate drought stress induction and alleviation mechanisms in treated plants.
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