Investigating on plasma polymerization of polyethersulfone membranes by ethylene for membrane distillation

摘要

A novel hydrophobic membrane was developed by means of plasma polymerization of the polyethersulfone (PES) membrane using ethylene as the precursor to obtain appropriate performance in the membrane distillation (MD). The effects of plasma treating parameters including duration time, gas pressure, and power on the surface properties of the treated membranes as well as their MD performances were discussed. The surface properties of the treated samples were evaluated in terms of the surface morphology, chemistry, porosity and pore size, roughness, hydrophobicity, and Liquid Entry Pressure (LEP). The treated hydrophobic PES membranes with water contact angles of as high as 115 degrees were obtained at high pressures and moderate powers. Response surface methodology was applied for modeling and optimization of the Air Gap Membrane Distillation (AGMD) system to separate benzene as a volatile organic compound from water. The plasma treated membranes showed fluxes at least as high as those of the commercial polytetrafluoroethylene (PTFE) membranes.