Graphitization modified three-dimensional fully interconnected high porous TiO2 ceramics: A promising carrier material for thermal storage and thermal conductivity enhancement

Abstract

In this work, porous TiO2 ceramics (PTC) and the graphitization modification of PTC (GPTC) with three-dimensional fully interconnected and uniform pore structure as a carrier for PCM was prepared by the Pickering emulsion method. Compared with PTC, the thermal conductivity and porosity of GPTCs were further improved and the specific surface area of GPTCs was increased by 5.7 times. The results of DSC curves showed that the melting and solidification enthalpy of PEG-GPTC20 were 143.8 J/g and 139.0 J/g, respectively, which only decrease by 0.68 % and 0.35 % after 100 phase change cycles. The experimental thermal conductivity of PEG-GPTC20 composites improved by 3.2 times. The results of non-isothermal crystallization kinetics revealed that the nucleation activation energy: PEG>PEG-PTC > PEG-GPTC, which indicated that GPTCs porous carrier encapsulation was beneficial to the nucleation process of PEG. The PEG-GPTCs composite phase change material designed in this paper has significant advantages in maintaining high thermal conductivity and heat storage performance at the same time while comparing other composites. Therefore, GPTCs are a promising carrier material for thermal storage and thermal conductivity enhancement.