Plasma-grafted anion-exchange membrane preparation and process analysis

A green and simplified plasma grafting approach was adopted for anion exchange membranes (AEMs) synthesis based on polyvinyl chloride powders in three steps: plasma bombardment, grafting and alkalization, avoiding the use of toxic chloromethyl ether and quaternization reagents. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses demonstrate the successful grafting of benzyltrimethylammonium groups into the polyvinyl chloride matrix. The plasma grafted AEM exhibits satisfactory thermal stability, chemical stability and ionic conductivity, suggesting potential application in fuel cell. The plasma bombardment efficiency reaches up to 50% based on the FTIR and XPS results, meaning that one in every three syndiotactic CH2-CHCI units is bombarded in the polyvinyl chloride matrix. But only a small part of plasma bombarded CH2-CHCI units are grafted with (vinylbenzyl)trimethylammonium chloride (VBTAC) monomer, indicating that the grafting efficiency is the performance limiting factor in the plasma-grafted AEM synthesis. We anticipate this finding will provide guidance of plasma grafting technique for AEM preparations. (C) 2016 Elsevier Ltd. All rights reserved.