Quick-Release Antifouling Hydrogels for Solar-Driven Water Purification

Abstract

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.

The dual nature of biomimetic melanin

“…Melanin-like materials, and in particular polydopamine (PDA), are finding outstanding applications in fields of high social and economic impact associated with human health, 1 energy conversion and accumulation, and environmental preservation. 2 The main reason for this success is that melanin-like nanomaterials combine an intrinsic biocompatibility with simplicity of preparation in their biomimetic forms, unique optical and electronic properties and unprecedented multifunctionality.…”

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

“…To enhance the LCST of NIPAm, amphiphilic ionic units were introduced and the mass ratio of monomers was optimized to address the unfavorable properties of NIPAm. Consequently, the LCST of NIPAm was increased to 36 °C. , As shown in Figures i and S3, the top temperature of the DCS-PNIPAm gel increased progressively over time when exposed to sunlight, reaching its LCST after 300 s. The temperature observed on the surface after a time period of 2000 s was around 40.3 °C, showing a rise of around 4.3 °C over its LCST. This rise in temperature facilitated the attainment of the water release condition.…”

Flexible Sponge Ball-like Temperature-Responsive Molecularly Imprinted Polymer with Self-Driven “Transformation Recovery” and Mechanism Exploration

“…Accordingly, the LCST of ST-SMIP was 35.67 °C, which was slightly higher than that of pure PNIPAM (32.0 °C) as previous reports . This occurred because the participation of auxiliary hydrophilic monomer MAA and GO prompted ST-SMIP with water molecules than pure PNIPAM, which led to polymer dehydration at a higher temperature . The low LCST of ST-SMIP that was close to room temperature would demonstrate the cost-effectiveness and achieved energy conservation effect in practical application.…”