화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.34, No.8, 1475-1482, 1996
Permselectivity Between 2 Anions in Anion-Exchange Membranes Cross-Linked with Various Diamines in Electrodialysis
A membranous copolymer crosslinked with divinylbenzene reacted with N,N,N’,N’-tetramethylethylenediamine, N,N,N’,N’-tetramethyl-1,3-propanediamine and N,N,N’,N’-tetramethyl-1,6-hexanediamine to prepare highly crosslinked anion exchange membranes. More than 80% of both tertiary amino groups of the diamines reacted with chloromethyl groups of the membrane to form crosslinkage. After formation of the high crosslinkage of the membrane was confirmed with dialysis of a neutral molecule, electrochemical properties of the obtained membranes (mainly, relative transport number between two anions in electrodialysis) were evaluated : nitrate ions to chloride ions, sulfate ions to chloride ions, fluoride ions to chloride ions, and bromide ions to chloride ions. Though larger anions, in general, were difficult to permeate through the membranes due to high crosslinkage, the number of methylene groups of the diamines (which means the increase in hydrophobicity of anion exchange groups) also affected the relative transport number between two anions. The lower the hydration of anions, the higher the relative transport number of the anions through the membranes with the hydrophobic anion exchange groups.