Flexible artificially-networked structure for ambient/high pressure solar steam generation

Abstract

The heat localization approach has promised a new route to solar steam generation with a higher efficiency than that of the current bulk heating approaches. In this approach, the material structure localizes the absorbed solar energy, forms a hot spot, and wicks the fluid to the hot spot for steam generation. The non-equilibrium nature of this approach minimizes energy losses leading to its superior performance compared to equilibrium approaches. However, to date, the generated steam is only at ambient pressure and not suitable for high pressure applications. Herein, we report development of a flexible artificially-networked material structure that is highly efficient for ambient and high pressure steam generation with integrity for large-scale and varied geometrical implementations. This flexible material is composed of a porous polymer skeleton coated with exfoliated graphite and artificially-networked 3D veins. The porous skeleton and the interconnected veins are developed in two distinct fabrication steps. The structure generates steam in the temperature range of 100–156 °C and at the pressure range of 100–525 kPa under solar irradiation. This material structure promises a robust and highly efficient approach for solar steam generation for both ambient pressure applications (e.g. solar ponds and desalination) and high pressure applications (e.g. power generation, solar cooling technologies, and hygiene systems).