Mechanically improved superhydrophobic nanofibrous polystyrene/high‐impact polystyrene membranes for promising membrane distillation application

Abstract

AbstractRobust membranes for commercial applications of membrane distillation (MD) are nearly the Achilles ankle of the process. Despite from high hydrophobicity requirements of the MD membranes, they must have enough mechanical and thermal stabilities. In this regard, flexible, superhydrophobic, and high‐productive nanofibrous membranes were fabricated using mixed dope solutions made of polystyrene (PS) and high‐impact PS (HIPS) through the electroblowing process. Although the PS nanofibers can be designed to have hierarchically rough surfaces to show superhydrophobicity, the inherent brittleness of this polymer still remains a big issue for practical application for a longer period of time. Upon adding HIPS into the PS‐containing dope solution, the rigid PS membrane turned into a more flexible one with improved elongation at break from 5.83% to 14.89%. Also, excellent direct contact membrane distillation performance was achieved using high saline (up to 150 g/L) and 0.1 mM sodium dodecyl sulfate/35 g/L NaCl feed solutions during 96 and 24 h, respectively. Superhydrophobicity (˃160°) and high LEP value (up to 173.2 kPa) gifted membranes with outstanding wetting resistance. Our proposed procedure can pave the route for the facile fabrication of robust MD membranes using cost‐effective materials and a high‐throughput fabrication process.