Effect of zirconium(IV) propoxide concentration on the thermophysical properties of hybrid organic-inorganic films

Abstract

In this work, micrometer-thick organic-inorganic hybrid films are fabricated. A photothermal experiment is designed and conducted to characterize the thermophysical properties of hybrid films, as well as the thermal contact resistance between the film and substrate. The molecular cagelike or nanopores, which can strongly enhance the phonon scattering, are considered to be formed inside the films during fabrication. The first order estimation of the volume fraction of cavities and its effect on thermophysical properties are obtained. The effect of zirconium(IV) propoxide (ZPO) concentration on the thermophysical properties of hybrid films is also studied. The effective (measured) thermal conductivity and thermal effusivity of hybrid films are close to those of polymethyl methacrylate (PMMA) films, and are not significantly affected by the added ZPO, which is used to adjust the optic properties of films. The extracted bulk thermal conductivity of the hybrid films is close or smaller than that of bulk PMMA, and shows certain thermal conductivity reduction by the ZPO addition. The thermal effusivity study indicates that the response of the surface temperature change to an abrupt heat flux across the surface of hybrid films will be similar to that of PMMA films.