Size and shape control of monoclinic vanadium dioxide thermochromic particles for smart window applications

摘要： Monoclinic vanadium dioxide (VO2 (M)) was synthesized by the thermolysis of vanadyl ethylene glycolate, which was obtained easily by the precipitation of a vanadium precursor in ethylene glycol solution under atmospheric conditions. The particle size and shape were easily controlled by altering the molar concentration of the vanadium precursor. Thereafter, VO2 (M) composite films were prepared by mixing with poly(vinylpyrrolidone). A high concentration of the vanadium precursor produced small spherical nanoparticles ≈30 nm in size, while lower concentrations afforded large rod-like particles. The composite films fabricated with the VO2 (M) nanoparticles exhibited high luminous transmittance (Tlum = 79%) and IR modulation ability (ΔTIR = 5.6%). This work demonstrates that these VO2 (M) composite films show promise for application in smart windows.