Quick-Release Antifouling Hydrogels for Solar-Driven Water Purification
Xiaohui Xu, Néhémie Guillomaitre, Kofi S. S. Christie, R. Kōnane Bay, Navid Bizmark, Sujit S. Datta, Zhiyong Jason Ren, Rodney D. Priestley
Abstract
High Resolution Image Download MS PowerPoint Slide Hydrogels are promising soft materials for energy and environmental applications, including sustainable and off-grid water purification and harvesting. A current impediment to technology translation is the low water production rate well below daily human demand. To overcome this challenge, we designed a rapid-response, antifouling, loofah-inspired solar absorber gel (LSAG) capable of producing potable water from various contaminated sources at a rate of ∼26 kg m –2 h –1, which is sufficient to meet daily water demand. The LSAG─produced at room temperature via aqueous processing using an ethylene glycol (EG)–water mixture─uniquely integrates the attributes of poly( N -isopropylacrylamide) (PNIPAm), polydopamine (PDA), and poly(sulfobetaine methacrylate) (PSBMA) to enable off-grid water purification with enhanced photothermal response and the capacity to prevent oil fouling and biofouling. The use of the EG–water mixture was critical to forming the loofah-like structure with enhanced water transport. Remarkably, under sunlight irradiations of 1 and 0.5 sun, the LSAG required only 10 and 20 min to release ∼70% of its stored liquid water, respectively. Equally important, we demonstrate the ability of LSAG to purify water from various harmful sources, including those containing small molecules, oils, metals, and microplastics.