A Microstructured Graphene/Poly(N-isopropylacrylamide) Membrane for Intelligent Solar Water Evaporation

Angew Chem Int Ed Engl. 2018 Dec 10;57(50):16343-16347. doi: 10.1002/anie.201810345. Epub 2018 Nov 14.

Abstract

Intelligent solar water evaporation (iSWE) was achieved with a thermally responsive and microstructured graphene/poly(N-isopropylacrylamide) (mG/PNIPAm) membrane. As the solar intensity varies, the water evaporation is tuned through reversible transformations of microstructures reminiscent of the stomatal opening and closing of leaves. Consequently, this mG/PNIPAm membrane displays a high water evaporation rate change (ΔWER) of 1.66 kg m-2 h-1 under weak sunlight (intensity<1 sun) and a low ΔWER of 0.24 kg m-2 h-1 under intense sunlight (1 sun<intensity<2 sun). Because of the double-layer structure with predictable shape and dynamics, the leaf-like membrane can further autonomously modulate the water evaporation by self-curling under intense solar irradiation in accordance with simulation results. This mG/PNIPAm membrane provides a smart material platform with self-adaptability in response to changing environments.

Keywords: irradiation; membranes; polymers; self-adaptive materials; water evaporation.