▎ 摘　　要

One of the major obstacles that hinder commercialization of membrane distillation (MD) for separation applications, especially for water desalination, is the limited adequate low-cost hydrophobic membranes. In this study, a novel poly(ethersulfone)/polyvinylidene fluoride (PES/PVDF) blend membrane and its composite with modified graphene nanoplatelets (GNPs) was fabricated using electro spinning technique. The fabricated pure and blend membranes as well as the composite membranes with GNPs were investigated using scanning electron microscope (SEM), X-ray diffraction analysis (XRD) as well as static water contact angle, liquid entry pressure and membrane porosity measurements. The average fiber diameter and the average membrane pore diameter were estimated using Image J software. A mathematical model was established and utilized to calculate the mass transfer coefficient for the different fabricated membranes at different feed flow rates. Moreover, membranes' MD performances were evaluated using a direct contact membrane distillation unit. The addition of only 2 wt.% GNPs into the PES/PVDF (3:1 w/w) blend increased its water contact angle up to 132.3 +/- 0.8 degrees. This composite membrane achieved a flux of about 19.35 kg/m(2).h at feed inlet temperature of 65 degrees C, flow rate of 30 l/h, and salt concentration of 10,000 ppm. The produced PES/PVDF/GNPs composite membrane showed a comparable performance to pure PVDF and PVDF/GNPs composite membranes. Although, a proper economic study is needed, the fact that commercial PES was used, which is relatively cheaper than PVDF, may make the PES/PVDF/GNPs composite membrane a viable candidate for MD applications.