Research Of Proton Exchange Membrane Based On PVA And PVDF In DMFC

Proton exchange membranes play important role in DMFC. This study is a new effort to meet the great need of preparing alcohol rejective proton exchange membranes.Polyvinyl alcohol (PVA)and polyvinylidene fluoride (PVDF) which have high resistivity to MeOH are chosen in experiments. Polyvinyl alcohol (PVA)- based membranes which are made in water and DMSO two different solvent and polyvinylidene fluoride (PVDF)- based membranes are prepared. MeOH permeability and conductivity,water content are all tested.It shows that the conductivity of Polyvinyl alcohol (PVA)- based membranes which made in water is better than that made in DMSO.But the methol permeality is higher than the latter. The addition of PWA improve blend membranes" conductivity greatly.In the situation of the same content of PWA,the alcohol rejectivity and conductivity of PVA-NanoSiO2-PWA membrane are worse than the(?) of PVA-TEOS-PWA which may result from the accumulation of Nano SiO₂.The accumulation of Nano SiO₂ can not make the components disperse symmetrically.PVA-PAMPS membrane shows good alcohol rejectivity , conductivity , high water content and mechanical intensity.The addition of PWA can not only improve the conductivity of the membranes based on PVDF but also enhance the permeability of MeOH.However the membranes based on PVDF show good conductivity and alcohol rejectivity.Some kinds of membranes such as PVA-TEOS-PWA, PVA-PAMPS and PVDF-TEOS-PWA show good conductivity and alcohol rejectivity and are expected to be used in DMFC.