Preparation And Investigation Of Polysulfone Diaphragms For Alkaline Water Electrolysis

The alkaline water electrolysis technology is mature according with the environmental protection requirements in the current hydrogen production, however, because of higher energy consumption, its application has been limited. The asbestos diaphragm which is widely used in the alkaline water electrolysis has high resistance and a risk of carcinogenesis and easy to pollute the electrolyte. Therefore, there is an urgent need to find new hydrogen membrane materials to reduce hydrogen generation costs.The author of this paper used the immersion precipitation phase-inversion method to prepare the polysulfone(PSF) membrane. Membranes were prepared with different pre-evaporation time, temperature of coagulation bath, PSF content, addition amount of PVP, ZrO2'additive level and thickness of the membrane. Then test the membranes'performance.The results show that when the pre-evaporation time is 15s ,the membranes have minimum resistivity, and the pre-evaporation time have less influences on the gas-barrier property , corrosion resistance and tensile strength; The resistivity and tensile strength were increased obviously, and Max. pore size was reduced as the increase of PSF content while has little influence on corrosion resistance. The Max. pore size and porosity were increased obviously, and The resistivity and tensile strength were decreased obviously as the increase of PVP addition. The tensile strength was decreased, the corrosion resistance and gas-barrier property were increased as the increase of ZrO2 content. When the ZrO2 content was higher than 50wt% , the hydrophilic properties get much better and the resistivity decreased obviously. The resistivity was increased obviously, the mechanical properties improved significantly as the increase of thickness while has little influence on corrosion resistance and gas-barrier property. The improved composition of the casting solution includes the solvent of NMP,15wt%PVP and 15%wt%PSF,60wt%ZrO₂. Proper pre-evaporation time is 15s and coagulation temperature is 15℃. To confirm the PSF membrane's actual availability, the Small-scale electrolysis experimental apparatus was applied with PSF membrane in different alkali concentrations and different alkali temperature. The results show that the cell voltage at a lower lever than asbestos diaphragm and gas purity at a high lever.