Preparation of PET track-etched membranes for membrane distillation by photo-induced graft polymerization

Abstract

New type of membranes with appropriate mechanical strength, thermal and chemical stability, high efficiency and hydrophobic surface are requisite for the development of membrane distillation (MD) applications. In this study hydrophobic track-etched membranes (TeMs) with pore size of 180 nm and thickness of 12 μm based on polyethylene terephthalate (PET) were prepared using photo-induced graft polymerization of silicon monomer such as triethoxyvinylsilane leading to increasing of contact angle up to 104°. The effect of monomers and additives concentration, time of grafting and aging on the surface morphology, pore size and contact angle were investigated by Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX) and goniometric analysis. The performance of the membranes was evaluated using direct contact membrane distillation (DCMD) process. The results show maximum permeate flux of 700 g/m2·h and 180 g/m2 h (dT = 75 °C) during 24 h saline solution operation (15 and 30 g/l respectively) with efficiency up to 99.3%.