Phase‐change composites silicone rubber/paraffin@SiO2 microcapsules with different core/shell ratio for thermal management

Summary A series of paraffin (Pa)@silicon dioxide (SiO 2 ) microcapsules with different core/shell ratios were constructed by interfacial‐polycondensation of tetraethoxysilane (TEOS) and γ‐Methacryloxypropyltrimethoxysilane (MPS), and then were embedded in addition‐cure liquid silicone rubber (ALSR) to fabricate ALSR/Pa@SiO 2 phase‐change composites. The SiO 2 shell can avoid the leakage of Pa. Meanwhile, the in‐situ modification of the SiO 2 shell by MPS can enhance the interface bonding between Pa@SiO 2 and ALSR, because the C═C bond introduced by MPS on the SiO 2 shell can participate in the curing reaction of ALSR. The study explored the effects of the core/shell ratio on the Pa@SiO 2 microcapsules and ALSR/Pa@SiO 2 composites. Differential scanning calorimetry analysis demonstrated that ALSR/Pa@SiO 2 composites have dependable thermal energy storage capability which can reach to 90.7 J g −1 and phase‐change enthalpy of the composites increase with the core/shell ratio. The ALSR/Pa@SiO 2 composites were found as form‐stable phase‐change materials with low leakage rate, which is attributed to the protection of both SiO 2 shell and ALSR matrix. Due to the chemical interfacial interaction, the composites displayed improved mechanical strength. The composites can be used for thermal management and temperature regulation as an electronic packaging material.