Temperature-Modulated Water Filtration Using Microgel-Functionalized Hollow-Fiber Membranes

In the present work, we investigate the potential of aqueous polymer microgels in membrane technology, especially for filtration applications. The poly(N-vinylcaprolactam)- based microgels exhibit thermoresponsive behavior and were employed to coat hollow-fiber membranes used for micro-and ultrafiltration. We discuss the preparation of microgel-modified membranes (by inside-out as well as outside-in filtration in dead-end mode). The clean-water permeability and stability of these membranes was studied not only as a function of time, but also of temperature. The microgel-modified membranes exhibit a reversible thermoresponsive behavior whereby both the resistance and the retention increased with decreasing temperature.