Oxygen-engineered AlN for thermally conductive PDMS composites

Aluminum nitride (AlN) has emerged as a promising filler for the fabrication of highly thermally conductive polymer composites due to its intrinsic high thermal conductivity and electrical insulation. Herein, the effects of oxygen content in combustion synthesized AlN and subsequent surface modification on the thermal and electrical properties of polydimethylsiloxane (PDMS) based composites were investigated. It is demonstrated that the thermal conductivity of the composite is enhanced with decreasing oxygen content in the AlN filler. Further functionalization with 3-aminopropyltriethoxysilane (APTES) yields a notable improvement in thermal transport, reaching 1.76 Wm −1 K −1 . Moreover, employing a binary hybrid filler system comprising Al 2 O 3 and AlN enables a substantial synergistic enhancement, elevating the thermal conductivity up to 4.2 Wm −1 K −1 .