Using advanced thermochromic technologies in the built environment: Recent development and potential to decrease the energy consumption and fight urban overheating

Abstract Construction materials play a crucial role in the thermal behaviour of the urban space as well as the building energy consumption and indoor environmental quality. Recently, there has been growing interest in optical construction materials/coatings as an effective method to minimise energy use, improve indoor and outdoor thermal comfort and fight urban overheating. Thermochromic materials as one of the advanced optical materials that change their optical properties/colour as a function of the ambient temperature can present lower/higher surface temperature than conventional materials during the warm/cold periods. Although pilot applications of thermochromic materials in the built environment shown a tremendous energy conservation potential, the serious optical degradation they exhibited, restricts seriously their use. Recent development in the field of thermochromic materials including quantum dots, plasmonics, photonic crystals, conjugated polymers, Schiff bases, liquid crystals, and nano optical filters for Leuco dyes present fascinating and impressive characteristics, enhance significantly the potential of thermochromic materials and opens new opportunities for the development and use of advanced cutting-edge optical materials. The present paper aims to offer a comprehensive overview of the recent developments on advanced thermochromic materials and on their energy conservation potential.