Preparation And Characterization Of Graphene Oxide Modified Intermediate Layer Of Bipolar Membranes

Bipolar membrane was composite membrane. Through the reverse voltage, the water in the intermediate layer could be decomposed into H+ and OH- which migrated into the solution through the cation exchange and anion layer separately. The bipolar membrane technology was simple, showing low waste emission. So the bipolar membrane technology has become a hot research in recent years. This had brought the breakthrough to the environmental pollution, chemical engineering, food engineering, etc. The application of membrane technology in foreign countries had been used widely. Due to the high cost of the preparation of a bipolar membrane, bipolar membrane was still limited in application in china. The study with high performance bipolar membrane had become a hot point in membrane in recent years.The paper took the new method-the automatic method and introduced the new material-Graphene oxide as the intermediate layer to prepare the new bipolar membrane. Compared with the casting method, the new method could make the bipolar membranes more uniform and thin. These factors had great influence on the voltage. Graphene oxide could be used as the intermediate layer of bipolar membrane because graphene oxide had a large number of Hydroxyl groups and carboxyl groups which could catalyze the water. The hydrogen bonding of bulk water in contact with the oxide materials induced the proton transfer, leading to a reduced activation barrier in water dissociation.By changing the preparation conditions of a bipolar membrane with single factor method and through the I-V curve test, the optical membrane was prepared and the voltage was 1.75V. The optimum conditions of bipolar membrane was prepared by spraying mass fraction as 0.3 of sodium polyacrylate, mass fraction as 2 of Glutaraldehyde, concentration as 2mg.mL-1 of grapheme oxide. The spraying time was set as 3s, and the spraying interval of two times was 60min. The result of contact angle test shown that the graphene oxide enhanced the hydrophilicity of the intermediate layer. The result of Electrodialysis test shown that the performance of water dissociation was improved. The result of thickness of intermediate layer test shown that the thickness of intermediate layer was thin. The result of the scanning electron microscopy shown that the surface of the membrane was uniform and thin. The swelling degree of the bipolar membranes shown that the membrane has the great stability in acid and alkali solution.