Synthesis of proton conductive inorganic-organic hybrid membranes through copolymerization of dimethylethoxyvinylsilane with vinylphosphonic acid

摘要

Proton conductive inorganic-organic hybrid membranes were synthesized from dimethylethoxyvi-nylsilane (DMEVS),vinylphosphonic acid (VPA) and 3-glycidoxypropyltrimethoxysilane (GPTMS) through copolymerization followed by sol-gel process.The ratio of phosphorus to silicon in the copolymer almost corresponded to the charged molar ratio of VPA to DMEVS when the ratio of VPA to DMEVS was below 1/2.Self-standing,homogeneous,highly transparent membranes were synthesized from DMEVS-VPA copolymer and GPTMS via sol-gel condensation.Differential thermal analysis-thermogravi-metry analyses indicated that these membranes were thermally stable up to 200 °C.The results of Fourier transform infrared and 13C NMR revealed that phosphonic acid groups of VPA were chemically bound to organ-osiloxane network.The copolymerization and condensation of (DMEVS-VPA)/GPTMS were confirmed by 31P and 29Si NMR spectra.The proton conductivity of the hybrid membranes increased with phosphonic acid content.The membrane of (DMEVS-VPA)/GPTMS showed a remarkable conductivity of 6.3 x 10~(-2) S cm~(-1) at 130 °C and 100% relative humidity.