Optical properties of smart thermochromic film by computational optical model

Thermochromic film is capable of modulating optical properties in response to environmental temperature. It has the potential to control solar heat gains in buildings and therefore to reduce energy consumptions. This study aims at investigating optical behaviors of thermochromic film using optical simulation. Thermochromic film is designed by incorporating thermochromic powders into polyvinyl chloride (PVC) matrix. The optical constants of both PVC film and thermochromic pigment are determined based on a series of reflectance and transmission measurement. The influence of powder concentration, temperature, and particle depth on normalized scattering and absorption cross section, forward scattering ratio, and diffuse reflectance of thermochromic film was investigated using optical simulation. These studies can serve as a model for understanding the interaction of light with thermochromic powder embedded in polymer matrix and facilitate the computer-aided design of thermochromic film with high thermochromic efficiency.