Hollow fiber membranes with hierarchical spherulite surface structure developed by thermally induced phase separation using triple-orifice spinneret for membrane distillation

Abstract Polyvinylidene fluoride (PVDF) hollow fiber membranes were developed by the thermally induced phase separation (TIPS) process using a triple-orifice spinneret with solvent co-extrusion at outermost channel for applications in membrane distillation (MD). The polymer surface concentration during preparation was controlled exploiting interfacial interactions of diluent and extruded surface. from dense to porous structure large pore size high porosity, which considerably enhanced water vapor permeability 13.5 L m?2 h?1. Furthermore, responsible formation spherulites different shapes, such as contacted spherulites, isolated humps. humps constructed novel hierarchical structure, created superhydrophobic that conferred upon PVDF remarkable wetting resistance MD toward low-surface-tension saline water. More significantly, all unique structures achieved one-step fabrication without additional processes materials. Thus, this work provides new, simple, useful alternative performances desalination.