Tailoring effect of aliphatic chain on the energy storage ability of azobenzene-containing surfactants

Key Words:Solar thermal fuel; Phase change material; Photon energy storage; Low-grade heat; Azobenzene

Abstract:Photon energy storage and low-grade heat collection are important for the sustainable energy utilization, which could be achieved by the development of photoswitches-based phase change materials. While, the phase change materials based on azobenzene exhibit a contradiction between gravimetric energy density and light-induced energy-charging ability. Here, a class of ammonium surfactants containing an azobenzene motif and different tail chains is designed and synthsized for harvesting photon energy and low-grade heat through photoresponsive phase change in solid state. The gravimetric energy density and energy-charging process of such surfactants could be well tailored by the tail chain. By UV-charging in solid state and solution state, the as-prepared surfactants could address the gravimetric energy density as high as 152.1 J g-1 and 218.7 J g-1, respectively, which are among the top level of azobenzene-based thermal fuels. Such surfactants could release the stored photon energy and low-grade thermal energy out as upgraded heat under Vis light, causing a fast and lasting environmental temperature rise. This work provides a new designing strategy for balancing the gravimetric energy density and energy-charging ability of azobenzene-based materials.

Volume:42

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Translation or Not:no