On the adsorption kinetics of an eco‐friendly surfactant n‐decyl‐β‐D‐maltopyranoside

Abstract

AbstractEco‐friendly surfactant alkyl polyglycosides (APGs) have garnered ample interest in the literature. However, the adsorption kinetics of APGs at an air‐water interface has not been studied to date. Consequently, this study aimed at investigating the adsorption kinetics of the APG n‐decyl‐β‐D‐maltopyranoside (β‐C10G2) at a freshly created air‐water interface. The dynamic and equilibrium surface tension (ST) of the aqueous β‐C10G2 solutions were experimentally measured at varying concentrations using a pendant bubble tensiometer and the ST data were examined via theoretical simulations using the Langmuir and Frumkin models. The fitting results revealed that the Frumkin model (with K = −2.9) well‐predicted the equilibrium ST data; signifying a considerable cohesive intermolecular force amidst the adsorbed β‐C10G2 molecules. The theoretical mixed‐controlled ST profiles (predicted by the Frumkin model) described the dynamic ST data reasonably well, but the adsorption rate constant increased significantly at increasing concentration. A comparison on the ST data of β‐C10G2 and β‐C12G2 (n‐dodecyl‐β‐D‐maltopyranoside) was also conducted and a relatively greater surface‐activity and lower cmc of the latter alkyl glycoside was observed.