PVA-Based Anion-Exchange Membranes [chapter]

Mitsuru Higa
2015 Encyclopedia of Membranes  
PVA-based anion-exchange membrane consists of poly(vinyl alcohol)(PVA) matrix and anionexchange groups (positively charged groups); hence, anions selectively permeate through the membrane. PVA is one of the most popular polymers that has been used as a membrane matrix, because a film made from PVA shows good physical properties, high hydrophilicity, process ability, biocompatibility, and good chemical resistance. PVA is a water-soluble polymer and does not have any anion-exchange groups. Hence,
more » ... a PVA-based homogenious anion-exchange membrane (AEM) can be prepared easily by casting an aqueous solution of mixed PVA and polycations and then cross-linked PVA polymer chains. PVA is a semicrystalline polymer; thus, heat-treatment above the glass-transition temperature increases the crystallinity of the polymer, which acts as a physical cross-linking. PVA chains can also be chemically cross-linked using cross-linking agents such as glutaraldehyde(GA) as shown in Fig. 1 . Hence, the degree of swelling of a PVA-based AEM, which plays an important role in its permselectivity for anions and membrane resistance, can be easily controlled by varying the
doi:10.1007/978-3-642-40872-4_514-1 fatcat:6dx2mzf2ffb6blwpwzjiksxnsy