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Nano-SiO 2 porous thermal insulating material (TIM) has drawn tremendous research interests due to its advantages of low density, high porosity and low thermal conductivity. However, its long-term stability in humid environment can be severely deteriorated by the high hydrophilicity resulting from tetrahedral coordination of oxygen and capillary effect of porous structure. It is still a great challenge to cost-effectively fabricate bulk TIM with superior hydrophobicity and consequent remarkable self-cleaning capability. Herein, via an oil-in-water microemulsion treatment, we have proposed a new strategy to construct 3D superior hydrophobic nano-SiO 2 porous TIM. The polymethylhydrosiloxane-modified TIM exhibits a large water contact angle of 166°, and corresponding excellent self-cleaning characteristic while maintaining low thermal conductivity of 0.031 W/m·K. Moreover, our high hydrophobicity of TIM exhibits excellent durability under high temperature up to 400 °C, high humidity of 100%, and chemical erosions. Detailed knowledge of the physical chemistry basis of the superior hydrophobic nano-SiO 2 porous TIM can provide great opportunity to fabricate advanced self-cleaning and heat insulating devices especially targeted for harsh environments. [ABSTRACT FROM AUTHOR]

This paper presents that polyethylene glycol (PEG) synthesizes a form-stable phase change material (FS-PCM) with high thermal conductivity and considerable heat storage density. PEG was confined to the chain structure of epoxy resin (EP) via high-temperature melt blending and curing, which solves the leakage problem of PCMs during phase transformation. In order to increase the thermal conductivity and stability of the PEG/EP while maintaining good heat storage capacity and insulation ability, a low loading of reticulated porous Al 2 O 3 ceramic (RPC) was introduced into the PEG/EP matrix. RPC increases the thermal conductivity of FS-PCM by 5.5 times and the heat storage rate by 4 times. In addition, FS-PCM filled with 13.8 vol% RPCs has a coefficient of thermal expansion (CTE) of 80 ppm/K at 85–150 °C -a decrease of 62% over the matrix. Furthermore, the BN network is formed on RPC by vacuum impregnation technology, which further improves the thermal conductivity. This novel FS-PCM has excellent comprehensive properties and does not need for case package, indicating great prospects in thermal management and thermal storage. [ABSTRACT FROM AUTHOR]