Short-Chain Modified SiO(2) with High Absorption of Organic PCM for Thermal Protection

Organic phase change materials (PCMs) have great potential in thermal protection applications but they suffer from high volumetric change and easy leakage, which require “leak-proof” packaging materials with low thermal conductivity. Herein, we successfully modify SiO(2) through a simple 2-step method consisting of n-hexane activation followed by short-chain alkane silanization. The modified SiO(2) (M-SiO(2)) exhibits superior hydrophobic property while maintaining the intrinsic high porosity of SiO(2). The surface modification significantly improves the absorption rate of RT60 in SiO(2) by 38%. The M-SiO(2)/RT60 composite shows high latent heat of 180 J·g(−1), low thermal conductivity of 0.178 W·m(−1)·K(−1), and great heat capacity behavior in a high-power thermal circuit with low penetrated heating flow. Our results provide a simple approach for preparing hydrophobic SiO(2) with high absorption of organic PCM for thermal protection applications.