Fabrication of thermochromic composite films using transition temperature controlled VO₂ fine particles

Abstract

A vanadium oxide based precursor fine powder was prepared by the reaction of vanadium metal and W-IPA H₂O₂ aqueous solution, and non-doped VO₂ or W-doped VO₂ fine powder was obtained by heat-treatment of the precursor powder at 650°C in an H₂/Ar atmosphere. Composite films were fabricated using the non-doped or W doped VO₂ fine powder and transparent urethane resin. The resulting composite films showed a reversible thermochromic property. The transition temperature of the composite using non-doped VO₂ powder was 68.9°C, and that of the composite using 1% W doped VO₂ powder was 46.3°C.