Modification of PES Polymeric Membrane by Oleic Acid for Membrane Distillation Process

In order to enhance the water flux and rejection of polyethersulfone (PES) membranes for membrane distillation process (MDP), we have developed a new PES membrane using a oleic acid as a hydrophobic agent. The synthesis membranes are fabricated via the phase inversion procedure and we examined the effects of oleic acid on hydrophobicity, porosity, surface roughness, morphology and MDP performance. For the membrane characterization, the produced membranes were characterized by contact angle, FTIR spectroscopy, field emission scanning electron microscopy, atomic force microscopy and porosity measurements. The outcomes demonstrated that the presence of the small amount of oleic acid in the membrane has led to an increment in the membrane hydrophobicity and porosity, and also improves the water flux and rejection of the MDP. The increment amount of oleic acid not only have no positive efficacy on the membrane performance, but can also reduce the MDP efficiency. In some areas, the excess concentration of oleic acid prevents the crossing of vapors evaporation through the cavities, so it will diminish the MDP flux.