Complexation between sulfonated polystyrene ionomers and bis(2-ethylhexyl) sulfosuccinate sodium salt (aerosol OT, AOT) surfactant molecules in m-xylene was studied by ultracentrifugation, vapor pressure osmometry, viscometry, and dynamic light scattering. When the dilute ionomer solution is mixed with the AOT soluti6n, complexation takes place for both the slightly aggregated state of AOT and reversed micelles of AOT containing water. In the presence of excess AOT molecules, some of the AOT are free from the ionomers, and there are well-defined limiting compositions for complexes of the ionomer and AOT and for those of the ionomer and AOT micelles. The limiting composition depends on the species of the salt or acid group of the ionomer and on the state of AOT before mixing. The composition was estimated to be 0.21-0.66 reversed AOT micelles per &/acid group for the ionomer-AOT micelle complexes and 14-23 AOT molecules per &/acid group for the ionomel-AOT complexes. AOT molecules were found to disrupt efficiently the cluster-forming contacts among &/acid groups, each of them encapsulating a single salt/acid group. The AOT micelles, however, do not completely disrupt the intrachain aggregation.
A systematic study of complexation reactions of sulfonated polystyrene ionomers containing up to 5 molar percent of polar chain units with various oil-soluble surfactants is carried out in low-polarity organic solvents. Dipole-dipole attractions of the components lead to the formation of complexes characterized by limiting compositions and an unusual polymer-colloidal morphology of joint clusters and/or micelles. The limiting compositions (cp) for the complexes formed between ionomers and surfactant of the same charge (bis(2-ethylhexy1)suIfosuccinate sodium salt), or nonionic surfactants (primarily aliphatic amines) are equal to 15-30 surfactant molecules per one ionomer salt/acid group on average, with cp depending on the hydrophilic-lypophilic balance of the components, the initial aggregation state of surfactant and the nature of low-polarity solvent. lonomersurfactant complexation is accompanied by disruption of self-contacts of ionomer salt/acid groups, leading to "unfastening" and expansion of the ionomer coils in dilute solution. The "driving force" of the ionomersurfactant complexation and the structure of the resultant complexes are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.