Velásquez Josmary, Evenäs Lars, Bordes Romain
Nouryon Surface Chemistry AB, Stenungsund, Sweden; Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
J Colloid Interface Sci. 2024 Dec 15;676:1079-1087. doi: 10.1016/j.jcis.2024.07.131. Epub 2024 Jul 16.
Limited research has been conducted on the influence of chelating agents on the self-assembly process in surfactant solutions. The traditional approach assumes the chelating agent only interferes as a salting-out ion, therefore promoting surfactant separation. However, the opposite behavior has been observed for iminodipropionate based surfactants, in which the presence of chelating agents of the aminopolycarboxylate type increases solubility of nonionic ethoxylated surfactants in mixed micellar systems. Specific interaction between chelating agents-surfactants can be an important parameter in the self-assembly processes.
Physicochemical properties of solutions containing amphoteric surfactant and tetrasodium glutamatediacetate have been investigated. Macroscopic properties, such as viscosity and cloud point, were evaluated in the presence of a non-water-soluble alkyl ethoxylated surfactant. Interactions between amphoteric surfactant and chelating agent were monitored by NMR spectroscopy, including C chemical shift and lineshape analysis as well as H diffusometry.
The study reveals that there is an interaction between the head group of the surfactant and the chelating agent forming oligomeric surfactant analogues with larger hydrophilic moieties, which results in smaller, more spherical micelles. The combined interactions provide possibilities for tuning the aggregation behavior of systems containing surfactants and chelating agents, and with that, the macroscopic properties of the system.
