The structure of the surface of anion-exchange membranes MA-40 and MA-41 after sorption of pectin

Abstract

This article is devoted to the influence of pectin's sorption on the surface of anion-exchange membranes' MA-40 and MA-41 condition during the electrodialysis of pectin-containing solutions. The surface's condition of the initial membrane and of the membrane sorbing pectin was researched by the method of scanning-force microscopy. The sorption of pectin by membranes causes a change in the uniformity of their surface. The membrane MA-40 has a more hydrophilic ion-exchange matrix containing secondary and tertiary nitrogen atoms. Therefore, it exhibits an increased affinity for molecules of pectin, which leads to the formation of a more uniform surface in the sorption process. The sorption of pectin on the less hydrophilic membrane MA-41 containing quaternary nitrogen atoms, on the contrary, reduces the uniformity of the surface. Thus, the observed changes of the state of the surface of anion-exchange membranes MA-40 and MA-41 after sorption of pectin are related to their different chemical nature.