Robust and Elastic Thermoresponsive Hydrogels with High Swelling Properties for Efficient Solar Water Purification

A viable and long-term method for producing clean water at hydrogel interfaces is solar-driven evaporation. This research utilizes the microgel polymerization technique to fabricate DCS-PNIPAm gels that exhibit exceptional swelling capacity and mechanical qualities. Electrostatic forces and hydrogen bonds between molecules occur between the sulfonic acid anions and ammonium cations inside the P(NIPAm-co-DMAPS) chains. Alginate is characterized by a high content of carboxyl and hydroxyl groups, which facilitate the establishment of hydrogen bonding and electrostatic interactions within the P(NIPAm-co-DMAPS) system. Semi-interpenetrating networks are formed in the hydrogel as a result of physical and chemical cross-linking brought on by these interactions. Consequently, the hydrogel's mechanical characteristics and swelling capacity were significantly enhanced, and the water-collecting rate of DCS-PNIPAm reached up to 9.32 kg m–2 h–1 under one sun irradiation. Notably, the sodium alginate (SA) and carbon nanotubes (CNTs) layer of the DCS-PNIPAm gel has excellent filtration properties, which can make it possible to use sunlight to purify water from various contaminated water sources containing dyes, oils, and metals.