Thermochromic superhydrophobic coatings for building energy conservation

Abstract

This work proposes to use a superhydrophobic coating with reversible thermochromic function as the surface coating of building envelope to reduce building energy consumption. The coating consists of Portland cement, thermochromic microcapsules (TCM) and other additives. The switching temperature (Ts) of the thermochromic coating is 30 °C. When T < Ts (in winter), the thermochromic coating is in the state of color development, with dark color and low solar reflectance; When T > Ts (in summer), the thermochromic coating is in the state of decolorization, showing a light color and a high solar reflectance. The the thermochromic coating is beneficial to building heating in winter and cooling in summer. In additional, the thermochromic coating has bright color and can change with the change of temperature, which has a strong decorative effect. Furthermore the coating surface has self-cleaning performance, which can prevent the deterioration of spectral reflectance caused by the accumulation of dust on the coating surface. The superhydrophobic coating has excellent corrosion resistance, mechanical stability and UV aging resistance. EnergyPlus energy consumption simulation results show that the thermochromic coating can effectively reduce the total annual energy consumption in cold winter and hot summer areas.