Controlling the formation of porous polyketone membranes via a cross-linkable alginate additive for oilin-water emulsion separations

摘要

Polymeric membranes with porous structures have attracted considerable attention in a wide range of research disciplines.Membrane separation is one of the essential applications which needs relatively precise control to realize the size-discrimination of feed mixtures.Nonsolvent-induced phase separation(NIPS)method1 generates pores during the polymer solidification process by the demixing of the viscous polymer solution.Employing aliphatic polyketone(PK)as the polymer matrix,a cross-linkable alginate additive(sodium alginate,SA)was doped into its solution to induce either accelerated or delayed demixing with the different initiation manners of cross-linking.PK membranes with controllable pore size distribution were accordingly obtained.Besides,the preserved alginate additive within the membrane matrix also improved the hydrophilicity,which is favorable for the water transport and fouling-resistant of pollutants.As a demonstration,the oil-in-water emulsion separation performances of the optimized membranes coincided well with the altered membrane pore structures and pore properties,showcasing the effectiveness of this feasible approach on the NIPS-derived polymeric membranes.This alginate-rendered control of phase inversion may also be applicable for the fabrication of other polymeric membranes requiring pore modifications.