Thermo-responsive membranes fabricated by immobilization of microgels with enhanced gating coefficinent and reversible behavior

Abstract

Thermo-responsive smart gating membranes have much potential applications in many fields, such as controlled release of drug, chemical/biological separation, sensors and water purification. In this study, a series of novel thermo-responsive membranes were fabricated through immobilization of thermo-responsive microgels into commercial microfiltration membranes via dynamic adsorption. The microgels were synthesized via precipitation polymerization of N-isopropylacrylamide (NIPAm), which can be reversibly expanded and shrunken upon the temperature change. This thermo-responsive behavior was preserved after incorporation of them into the membrane, indicating reversible water flux between the pore closure state at 25 °C and the pore opening state at 40 °C and high stimuli-responsive gating coefficient of 41 under narrow temperature range (25 °C–40 °C). More importantly, the resultant membrane exhibits good thermo-tunable separation performance for the polystyrene (PS) nanoparticles with different size, which has bright potential for the application in water gating and controlled release systems.