Accelerating weathering and thermal regulation performance of window frame applied with microencapsulated phase change thermochromic pigment coated wood material

Abstract

This study examines the impact of phase-change thermochromic (TC) coatings on the durability, color stability, and thermal regulation of poplar wood, focusing on potential applications in energy-efficient buildings. By applying accelerated weathering tests, the study assessed how TC pigments (red or yellow) at varying concentrations affect wood properties. The results showed that TC-treated wood undergoes significant color shifts depending on pigment concentration and temperature. For instance, at 25 °C, the color change (ΔE∗) reached 71.07 for red-20 samples and 68.30 for yellow-20, with increased lightness (L∗) at higher temperatures. Unlike untreated samples, TC-coated wood exhibited a whitening tendency as temperatures rose to 38 °C and 50 °C, suggesting a promising thermal regulation capability. Accelerated weathering tests revealed that TC-treated wood experienced greater color changes than control samples, though varnish coating helped reduce discoloration. Notably, thermal regulation tests demonstrated that TC-treated wood helps maintain cooler indoor temperatures during hot conditions and warmer temperatures in cold conditions, highlighting potential energy efficiency in building environments. This study provides a foundation for utilizing thermochromic materials in construction, offering insights into their weathering and thermal performance. Future studies should focus on optimizing TC formulations and assessing durability in real-world settings.