A single step fabrication of bio-inspired high efficiency and durable water harvester made of polymer membranes

Abstract

Inadequate fresh water supply in this planet has created a pressing need for developing a high-performance water harvester. To address this issue, inspired by Namib Desert beetle, an artificial hydrophobic/hydrophilic porous water harvester was successfully fabricated in this work via a facile single step approach of electrospinning PVDF/PAN composite solutions. The wetting phenomenon of as-spun bead-free nanofibers was evident that there was formation of novel wettability containing both hydrophobicity and hydrophilicity, and then the water collection test results demonstrated the formation of hydrophobic/hydrophilic membranes could significantly enhance the water harvesting efficiency. Highest water harvesting efficiency of ~315 mg/cm2/h was obtained from PVDF/PAN composite membranes, which was 3 times that of the virgin PVDF in this work. The hydrophobic/hydrophilic phase ratios (by altering the weight ratio of PVDF/PAN) will also decide the wettability of as-spun membranes, eventually affect the water harvesting ability.