Poly(N-isopropyl acrylamide) (PNIPAm) hydrogels are soft thermoresponsive materials useful in fields ranging from human health to planetary health and are promising towards achieving sustainable and off-grid water purification. However, their use is limited by slow water uptake and release rates due to their closed-pore structures. Thus, we seek to tune the hydrogel network structures through the introduction of different non-solvents and salts to the polymerization medium. We demonstrate that these non-solvents and salts have a direct influence on hydrogel morphology (e.g. pore size and shape), and lead to the formation of open-pore architectures. Notably, these structural changes result in a marked improvement in water uptake and release rates compared to conventional PNIPAm hydrogels. With faster water transport enabled by the open-pore structure, these modified PNIPAm hydrogels have great potential in facilitating the increased application of hydrogels in the field of water purification.
