Filtration Through Thermo-sensitive Hydrogel Membranes*

Abstract

Poly(N-isopropylacrylamide) (PNIPAM) hydrogel is an attractive material because of its thermo-responsive properties. It is capable of changing its shape and wettability according to water temperature, which holds great promise for the development of advanced filter media.  In this study, PINIPAM hydrogels were specifically designed and transformed in filter membranes for applications in water filtration systems. These thermally-responsive filter membranes potentially facilitate enhanced filtration efficiency, selectivity, and the overall system performance. Here, we adopted two different procedures to form water-insoluble thermo-responsive filter media based on PINIPAM hydrogels: cross-liking and copolymerization. The PINIPAM hydrogels were electrospun, resulting in formation of thermo-responsive water-insoluble nanofiber membranes. These membranes underwent a series of comprehensive experiments to assess their performance and characteristics, including the mass loss measurements, water droplet infiltration for the wettability assessment, filtration tests, shrinkage measurements, and microscopic observations. These diverse experiments yield a thorough understanding of the PINIPAM nanofiber membranes' properties and their potential applications in water filtration systems.