NIR‐shielding films based on PEDOT‐PSS/polysiloxane and polysilsesquioxane hybrid

ABSTRACT Near‐infrared (NIR)‐shielding films based on polysiloxane or polysilsesquioxanes and poly(3,4‐ethylenedioxythiophene)‐poly(4‐styrene sulfonate) (PEDOT‐PSS) were synthesized via a sol–gel reaction. Phase‐separated mixtures of tetraethyl orthosilicate (TEOS) or methyltriethoxysilane (MTES) with an aqueous dispersion of PEDOT‐PSS formed deep‐blue homogeneously dispersed sols after stirring. Thin films were prepared by depositing the resulting homogeneously dispersed sols on a glass substrate by spin coating and heating. PEDOT‐PSS/TEOS films maintained uniform flat surfaces after 10 coatings. MTES‐based films exhibited mottled patterns with nonuniform surfaces. The 10‐layer TEOS‐based film has high NIR‐shielding properties with moderately visible transmittance. NIR absorption by the PEDOT‐PSS/TEOS hybrid suppresses air temperature elevation. The five‐layer TEOS‐based film showed similar NIR‐shielding ability and slightly lower visible light transmittance compared with tin‐doped indium oxide glass. The 10‐layer TEOS‐based film exhibited a 15.6% lower temperature rise than the uncoated glass substrate. Specifically, this is an environmentally friendly NIR‐shielding material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48367.