Preparation and Conducting Behavior of Amphibious Organic/Inorganic Hybrid Proton Exchange Membranes Based on Benzyltetrazole

摘要

A series of novel amphibious organic/inorganic hybrid proton exchange membranes with H3PO4 doped which could be used under both wet and dry conditions was prepared through a sol-gel process based on acrylated triethoxysilane(A-TES)and benzyltetrazole-modified triethoxysilane(BT-TES).The dual-curing approach including UV-curing and thermal curing was used to obtain the crosslinked membranes.Polyethylene glycol(400)diacrylate(PEGDA)was used as an oligomer to form the polymeric matrix.The molecular structures of precursors were characterized by 1H,13C and 29Si NMR spectra.The thermogravimetric analysis(TGA)results show that the membranes exhibit acceptable thermal stability for their application at above 200 ℃.The differential scanning calorimeter(DSC)determination indicates that the crosslinked membranes with the mass ratios of below 1.6 of BT-TES to A-TES and the same mass of H3PO4 doped as that of A-TES possess the-Tgs,and the lowest Tg(-28.9 ℃)exists for the membrane with double mass of H3PO4 doped as well.The high proton conductivity in a range of 9.4-17.3 mS/cm with the corresponding water uptake of 19.1％-32.8％ of the membranes was detected at 90 ℃ under wet conditions.Meanwhile,the proton conductivity in a dry environment for the membrane with a mass ratio of 2.4 of BT-TES to A-TES and double H3PO4 loading increases from 4.89× 10-2 mS/cm at 30 ℃ to 25.7 mS/cm at 140 ℃.The excellent proton transport ability under both hydrous and anhydrous conditions demonstrates a potential application in the polymer electrolyte membrane fuel cells.