Matthias Van Zele1 Klaartje De Buysser1

1, Ghent University, Ghent, , Belgium

In recent years, the need for smart window materials that lower the energy consumption for heating, venting and air-conditioning of buildings has grown immensely. These smart materials undergo a reversible change in physical properties depending on various conditions. A material that fits this description is vanadium dioxide, a thermochromic material that changes from a monoclinic to a rutile phase when heated above a critical temperature. This metal-insulator transition (MIT) leads to the reflection of infrared radiation. By reflecting this, a lower amount of heating-up occurs inside buildings and less cooling is needed.[1] In recent years, interest for this material has grown immensely.[2]
During this work, the main focus is the development of novel and easy methods to synthesize thermochromically active vanadium dioxide nanoparticles. Microwave syntheses were performed and optimized. The influence of various reaction parameters on the morphology, crystal structure and thermochromic properties of the nanosized materials was studied.
After synthesis, these nanoparticles are incorporated in an inorganic matrix. This mixture of nanoparticles and inorganic matrix material is deposited on flexible polymeric substrates. This method implies a facile scale up towards industrial production of smart window films. The inorganic matrix of choice is scratch resistant, which leads to optimized protection and prolonged lifetimes of said polymeric smart window films.

[1] A. Gonçalves. J. Resende. A. C. Marques. J. V. Pinto. D. Nunes. A. Marie. R. Goncalves. L. Pereira. R. Martins, E. Fortunato, Solar Energy Materials and Solar Cells 150 (2016) 1.
[2] M. M. Seyfouri, R. Binions, Solar Energy Materials and Solar Cells 159 (2017) 52.