PVDF-graphene conductive composite membrane and PVA-graphene conductive composite membrane preparation and application

Abstract

Graphene has a great potential to revolutionize many fields because of its perfect electrical conductivity. Therefore, it is considered a possible material for the preparation of conductive membrane. In this research, polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA) were used together with graphene to create graphene based polymer composite conductive membrane. First, Boehm titration was used to determine the linkage of carboxyl groups on the surface of graphene sheet. Then pure PVDF membrane was trail-produced to investigate the best ratio of PVDF, plasticizer, and solvent. Results showed that PVDF amount should not be higher than 15% by weight. In addition, the breaking stain and the contact angle increased with increasing plasticizer concentration; whereas the ultimate force decreased. The resistance of PVDF-graphene membrane was measured. Results showed that although the whole membrane became conductive, the resistance was not less than 8000 ohm. PVA-graphene membrane was prepared. This membrane had much lower resistance than the PVDF-graphene membrane. However, PVA-graphene had a bad performance in perchlorate adsorption due to lack of inside area. Besides, it could not prevent membrane blocking in dead-end electrical filtration. Based on calculation, if charged particles were held into electric field, at least 118 V must be used in dead-end electrical filtration. But with a cross flow filtration equipment, only 1 to 2 V was needed. Further research should be taken about investigating physical properties of those conductive membranes and their applications.