Development of graphene-PVDF composite membranes for membrane distillation

Abstract

A novel PVDF-graphene composite membrane has been developed. Specifically, a commercial PVDF polymer has been suitably functionalized with the aromatic rings of styrene (PVDF-f) and characterized by spectroscopic techniques. This new material has been used as a base for the adhesion of graphene, owing to the interaction between graphene and the aromatic rings of PVDF-f. The new PVDF-f and PVDF-f-graphene (PVDF-f-G) polymers were, then, used for the preparation of porous membranes by phase inversion technique and extensively characterized by morphological, surface and chemical-physical techniques. They displayed different properties in terms of hydrophilicity, pore size and mechanical resistance. When applied in direct contact membrane distillation (DCMD), in particular, the PVDF-f-G membranes showed long-lasting salt rejection (higher than 99.9%) and higher stability in time.