Effect of polymer molecular weight on structure and performance of PVDF hollow fiber membranes prepared via TIPS process with co-extrusion of solvent using triple orifice spinneret

摘要

Co-extrusion of solvent at the outer layer of the extruded polymer solution has shown considerable improvement in hollow fiber membrane characteristics in the thermally induced phase separation(TIPS)process,especially pure water permeability stability.It is crucial to consider the polymer solution properties in the co-extrusion process [1].In this work,the effect of the poly(vinylidene fluoride)(PVDF)molecular weight(MW)and concentration on the penetration depth and amount of the extruded solvent(PC),and the overall performance of the fabricated hollow fiber membranes were evlauted.To obtain an appropriate membrane with considerable water permeability stability,choosing appropriate polymer MW and concentration is inevitable to induce a special desired structure at the underneath of the membrane.