A well-designed polystyrene/polycarbonate membrane for highly saline water desalination using DCMD process

A novel porous polycarbonate (PC) membrane was fabricated using ethanol as non-solvent deploying immersion-precipitation process. To further increase surface hydrophobicity, polystyrene (PS) microbeads were sprayed on PC support using an air-assisted electrospraying process. Due to the micro/nano roughness of the PS layer, the formed dual-layer PS/PC membrane possessed outstanding wetting resistance over the neat PC membrane. The water contact angle (WCA) of the neat PC and PS/PC membranes was measured as 95.2 and 155.1 degrees, respectively. Liquid entry pressure of water represented a considerable enhancement of 84.6% compared to the neat membrane. Direct contact membrane distillation (DCMD) evaluation was performed using the fabricated and commercially available polytetrafluoroethylene (PTFE) membranes. Using concentrated saline water as feed (150 g/L), only PS reinforced PC (PS/PC) membrane showed nonwetting capability with stable DCMD performance during continuous long-term DCMD evaluation. Superhydrophobicity of PS/PC not only diminished pore wetting but also increased permeate flux considerably (45.9%up arrow) to produce high-quality permeate flux (<4.6 mu S/cm). Considering these attributes, using the low-cost PC polymer along with the high-productive air-assisted electrospraying process is a facile mute to fabricate decent membranes for the membrane distillation (MD) process.