2010 Volume 64 Issue 5 Pages 244-249
Ion-exchange membranes with a semi-interpenetrating network structure were prepared by blending poly (vinyl alcohol) (PVA) and polyelectrolytes. The membranes obtained were physically cross-linked by annealing them at various temperatures and chemically cross-linked by reaction with glutaraldehyde aqueous solutions to obtain heterogeneously cross-linked structure in the membrane. The charge density of the membrane increased with increasing polyelectrolyte content, annealing temperatures and the concentration of a cross-linker agent.
The permeability coefficient of methanol through the PVA-based cation-exchange membrane was 30 times lower than that of Nafion®117 under the same conditions. The PVA based membrane had about 3 times higher proton permselectivity than Nafion®117.
A bipolar membrane and a charge mosaic membrane were also prepared by pasting PVA-based cation-exchange layers and anion-exchange layers. The permselectivity for salt through the PVA-based charge mosaic membranes was more than 30 times higher than the charge mosaic membrane Desalton® (Tosoh Co. Ltd.)
The PVA based ion-exchange membranes can be prepared more cheaply and have more anti-fouling properties than commercially-available ion-exchange membranes prepared from styrene- divinylbenzene based resin. Hence, the PVA based membranes will have potential application to the desalination of salt water or purification of biochemical materials or food additives.
