The lack of fresh water resources is attracting concern worldwide. Recently, to address this global issue, researchers proposed the heat localization concept for interfacial solar seawater desalination in 2014. Since then, interfacial solar steam generation (ISSG) devices have attracted much attention, due to their potential for achieving highly enhanced optical‐thermal conversion through a single interface as compared with traditional solar seawater desalination. To date, the promising prospect of ISSG systems in seawater desalination has stimulated the rapid development of solar desalination technology based on heat localization. To comprehensively recognize ISSG devices and acquire more insights into their design associated with biological relevance, efficiency improvement, and applications, this review summarizes the progresses and prospects of ISSG devices in relation to the evolution of advanced materials, the engineering architecture, the collaborative application, and the current challenges.

Abstract:As the interface between human and machine becomes blurred, hydrogel incorporated electronics and devices have emerged to be a new class of flexible/stretchable electronic and ionic devices due to their extraordinary properties, such as softness, mechanically robustness, and biocompatibility. However, heat dissipation in these devices could be a critical issue and remains unexplored. Here, we report the experimental measurements and equilibrium molecular dynamics simulations of thermal conduction in polyacrylamide (PAAm) hydrogels. The thermal conductivity of PAAm hydrogels can be modulated by both the effective crosslinking density and water content in hydrogels. The effective crosslinking density dependent thermal conductivity in hydrogels varies from 0.33 to 0.51 Wm −1 K −1 , giving a 54% enhancement. We attribute the crosslinking effect to the competition between the increased conduction pathways and the enhanced phonon scattering effect. Moreover, water content can act as filler in polymers which leads to nearly 40% enhancement in thermal conductivity in PAAm hydrogels with water content vary from 23 to 88 wt %. Furthermore, we find the thermal conductivity of PAAm hydrogel is insensitive to temperature in the range of 25-40 • C. Our study offers fundamental understanding of thermal transport in soft materials and provides design guidance for hydrogel-based devices.

Solar-powered water desalination has been considered as one of the most promising solutions to alleviate clean water scarcity. In concentrated brine, the strong hydration ability of ions increases the required...

Hydrophilic acrylamide-based hydrogels are emerging platforms for numerous applications, but our ability to fully exploit these materials is currently limited. A deepening of our understanding of molecular-level structure/property relationships in hydrogels is crucial to progressing these efforts. Such relationships can be challenging to elucidate on the basis of experimental data alone. Here, we use molecular simulations as a complementary strategy to reveal the molecular-level phenomena that govern the thermo-mechanical properties of hydrogels. We focus on acrylamide-based hydrogels cross-linked with N,N'methylenebisacrylamide, generated using our previously-established computational crosslinking procedure. We find the water content to be a key determinant in the elastic response of these hydrogels, with enhanced tensile and shear properties at low water content. However, we also find increasing water content enhances the hydrogel's thermal conductivity, with the dominant contribution arising from the non-bonded contributions to the heat flux. In addition, chemical cross-linking improved the heat transfer properties of the hydrogel, whereas a reduction in convective heat transfer was predicted with an increase in hydrogel crosslinking. Our simulations provide a rational basis for designing and testing customized hydrogel formulations for maximising both thermal conductivity and mechanical properties.