Thermally Conductive Hybrid Nanoparticles - Fe2O3 and CNTs for Improving the Thermal Conductivity of Silicone Elastomers

摘要

Thermally conductive silicone based adhesives find a broad range of applications, e.g., as bondable heat sink components. With polydimethylsiloxane (PDMS) as the matrix and the thermally conductive hybrid nanoparticles - carbon nanotubes (CNTs) and iron oxide (Fe2O3), in this work, PDMS/Fe2O3/CNT ternary nanocomposites at different filler loadings are fabricated. The thermal conductive properties of the nanocomposites are characterized by a laser flash thermal physical property system and differential scanning calorimetry (DSC). The morphology/structures of the nanocomposites are examined by scanning electron microscopy (SEM). A statistical design of experiments (DOE) - mixture design has been used to elucidate the effect of the nanofiller loadings. The structure-property relationship studies reveal that: 1) when Fe2O3 loading is low (< 10 parts), the thermal conductivity enhancement of the ternary composite is dominated by CNTs; 2) the island (Fe2O3) - bridge (CNT) network structure are formed when the Fe2O3 loading is high, which results in a synergistic effect between CNT and Fe2O3 nanoparticles to offer the composite a significant improvement on its thermal conductivity.