Macromolecular complexes consisting of poly(aluminum chloride), [2‐(diethylamino)ethyl]dextran hydrochloride, and potassium poly(vinyl sulfate)

Abstract

AbstractThe mixture of poly(aluminum chloride) (PAC) and [2‐(diethylamino)ethyl]dextran hydrochloride (EA) were allowed to react with potassium poly(vinyl sulfate) (PVSK) to form many different water‐insoluble macromolecular complexes (MCs) in aqueous solution at various hydrogen ion concentrations. According to elemental analyses, IR spectroscopy, and solubilities of MCs, molecular structures of each MC depend on [H+]. It is suggested that the MCs obtained at pH 1.0 are products consisting of EA, PVSK, and aluminum aquo‐complex having coordination water whereas the MCs at pH 4.0 are higher molecular products consisting of EA, PVSK, and basic aluminum maltidentate complex. This result is attributable to change with [H+] in the degree of dissociation and conformation of EA, PVSK, and the dissociation of hydrated coordination of PAC. MC membranes were made by casting solutions of all kinds of MCs, and active, selective transport phenomena through a membrane of the MC prepared in a solution of pH 1.0 HCl were investigated under various conditions. Transport ratio of Na+ and the electric potential difference between the left and right sides of the membrane were measured, with a result that the higher value the membrane potential difference was long allowed to maintain, the higher the transport ratio became. According to this result, the driving force of transport is dependent on the membrane potential, Donnan potential, and diffusion potential, between both sides of the membrane. The Cl− exclusion (Donnan exclusion), however, is small due to the small cation‐exchange capacity, so that the membrane potential difference is caused to decrease rather rapidly by Cl− permeation. It was also suggested that the affinity of the carrier and both the chemical and physical properties of the MC membrane controlled the selective transport through the membrane.