TUNING SUBSTRUCTURE AND PROPERTIES OF DYNAMICALLY RESPONSIVE MULTIFUNCTIONAL ASYMMETRIC TRIBLOCK TERPOLYMER MEMBRANES
The hybrid process of block copolymer (BCP) self-assembly and non-solvent induced phase separation (SNIPS) is widely used for the fabrication of ultrafiltration (UF) membranes due to its commercial scalability and assurance of high permselectivity. Since its inception, there have been numerous efforts to expand the functionality of SNIPS membranes via additive incorporation, surface coating, or synthesis of more chemically-diverse BCPs. This study focuses on the synthesis of a poly(styrene)-b-poly(4-vinylpyridine)-b-poly(propylene sulfide) (SVPS) triblock terpolymer and the fabrication and optimization of SNIPS membranes derived therefrom. The resultant membranes, lined with narrowly-dispersed, hexagonally-ordered pores, displayed pH-responsive behavior and covalent binding capabilities reflective of the block chemistries. To further extend the applicability of these membranes, parameters such as evaporation time, polymer concentration, and solvent system composition were systematically varied to achieve a spectrum of substructure morphologies and permeability profiles while maintaining top surface order.