SURFACE MODIFICATION OF POLYVINYLIDENE FLUORIDE (PVDF) MEMBRANES BY LOW-TEMPERATURE PLASMA

摘要

In order to control surface pore sizes of polyvinylidene fluoride (PVDF) membranes and their distribution, low temperature plasma-induced grafting modifications of PVDF were studied to prepare hydrophobe membranes. By argon (Ar) treating and subsequent grafting reaction, a hydrophobe monomer, styrene, was introduced onto PVDF membrane. The structure and chemical composition at the PVDF surface were characterized by reflection FTIR. The surface modifications of PVDF were investigated by scanning electron microscope (SEM), atomic force microscopy (AFM) and differential scanning calorimeter (DSC). The effectiveness of modification and the chemical changes at the modified surface was studied under different plasma operating variables and graft reaction conditions such as plasma time and graft time. It was revealed that styrene monomers were successfully grafted onto PVDF membranes. The water permeability was measured by PVDF membrane modified in different graft condition. With the increasing of plasma time and graft time, the pores in the modified membranes became smaller and the distribution of pores narrowed, and the pure water flux decreased.