رفتارهای ساختاری، مکانیکی و حرارتی آلیاژهای نانو کامپوزیت نوولاک / گرافن اکسید

Main microstructural properties of organic aerogels dictate the thermal degradation of these materials. Incorporating of nanomaterials into the structure of organic aerogels can result in controlling and engineering the microstructural characteristics and as a result, the thermal degradation of organic aerogels. Here, the role of graphene oxide (GO) presence on the microstructure and morphology of novolac/GO nanocomposite aerogels is investigated. Although, the presence of GO nanosheets results in an enhancement of the density, but the specific surface area of aerogels increased with the contents of loaded-nanosheets, due to the high available surface area of GO nanosheets. The sol-gel polymerization of novolac resin in the presence of GO nanosheets results in formation of colloidal nanoparticles on the surface of GO nanosheets. Chemical characterizations confirm that the reason behind this phenomenon is the formation of covalent interactions between polymer chains and GO surface. Moreover, the thermal degradation and thermal conductivity behaviors of novolac/GO nanocomposite aerogels are studied here, to investigate the influences of GO presence on the heat-transfer mechanism through the aerogel. Thermal studies approve that the heat transfer depends strongly on the reduction of GO nanosheets, as well as on the contents of loaded-GO. As the contents of loaded-GO reach a percolation threshold, the structural characteristics, and consequently, the mechanism of thermal degradation throughout aerogel structure, change.