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

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. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48367.