Mesoporous Nanogel Sprays as Universal Evaporation Interface Modifiers for Boosting Water-Cluster Evaporation

Abstract

Accelerating water evaporation is vital for processes like photosynthesis, dehydration, and desalination. Optimizing the pore structure and interfacial properties of evaporative materials can reduce evaporation enthalpy and increase efficiency. However, integrating the evaporation interface with water transport channels poses significant design challenges and complicates low-enthalpy evaporation analysis. To address these challenges, a hydrophilic nanovesicle gel is developed with a hydrophobic mesoporous structure as an ideal spray. This spray effectively upgrades their interface of universal substrates (including PVA hydrogels, balsa wood, nanofiltration membrane, cellulose paper, nylon fabrics, etc.), enabling the simple preparation of evaporation materials. The sprayed samples, at a low spraying dose of 40 mg cm⁻², achieved evaporation rates of 1.58 and 3.26 kg m⁻² h⁻¹ under 0.5 and 1 sun irradiance, which are 297% and 268% higher than their respective substrates. These nanogels offer benefits like edibility, low cost, ease of use, and compatibility with various substrates, showing great potential in seawater desalination, dehydration technology, crop yield enhancement, and coating/paint drying. More importantly, this work highlights the need for researchers to focus on the surface structure of materials, rather than merely using bulk gels, in the development of high-performance evaporative materials.