Interactions between quaternized chitosan and surfactant studied by diffusion NMR and conductivity

Abstract

Surfactant-polysaccharide complexes (SPEC) based on oppositely charged sodium 1-decanesulfonate and quaternized chitosan were studied using two techniques. The first one, the conductivity, is a very often used even when diffusion NMR (DOSY) technique was considered for the first time for such systems involving surfactant and chitosan derivatives and more generally polysaccharides. The physico-chemical characteristics of pure surfactant solutions as well as SPECs were determined and compared according to the considered experimental technique. Close results were obtained and the great advantage of DOSY technique is the capacity to study simultaneously the two components of the systems, allowing more information on the nature of interactions between the surfactant and the polysaccharide as well as the mechanism involved during these interactions. This may be of great interest to understand how these complexes can alter the properties of formulations in which these components are involved, which is one of the big challenges of the industrial research.

Keywords: Conductivity; Diffusion NMR; Quaternized chitosan; Surfactant-polysaccharide interactions.