Facile synthesis of functionalized boron nitride nanosheets for photo-cured 3D printing of high thermal conductive composites

Addressing the concern of heat accumulation in electronic devices, considerable research efforts have been dedicated to develop composites that are thermally conductive yet electrically insulative. Incorporating hexagonal boron nitride (h-BN) as fillers shows promise in enhancing the thermal conductivity of polymer composites. However, notable challenges arise from difficulties in achieving well dispersion and establishing efficient three-dimensional thermal conductive networks. This work demonstrated an efficient photocurable direct ink writing (DIW) printing method to fabricate functional h-BN nanosheets (A-BNNS)/epoxy acrylate (EA) resin-based thermal conductive composites (A-BNNS/EA). Apple polyphenol-assisted ball milling was employed to fabricate functionalized BN nanosheets (A-BNNS). Subsequently, A-BNNS/EA inks were 3D printed using DIW to create thermally conductive composites, which were then UV-cured. The composite containing 55 wt% A-BNNS demonstrated an impressive thermal conductivity (TC) of 3.44 W/(m K). The utilization of 3D printing technology enables an onion-like dispersion of A-BNNS within the polymer matrix, effectively constructing three-dimensional thermal conductive networks. This contribution significantly enhances the overall thermal conductivity.