Magnesium-induced preparation of boron nitride nanotubes and their application in thermal interface materials.

The effective growth of boron nitride nanotubes (BNNTs) by boron oxide chemical vapor deposition (BOCVD) is extremely challenging, especially in a horizontal tube furnace. Herein, we propose a novel Mg-induction strategy, which is low cost and efficiently generates BNNTs by separating Mg from diverse boron sources (B2O3, H3BO3, borates, and so on). After careful analysis and discussion of the prepared BNNTs, the corresponding in situ generation of MgB2, an effective catalyst for the growth of BNNTs, was proposed and verified. This contribution will provide a low-cost, highly efficient and large-scale method for the preparation of BNNTs with the CVD method. The prepared BNNTs can be widely used in thermal interface materials, as demonstrated by the high thermal conductivity of the poly-vinyl alcohol (PVA) composite filled with these BNNTs. Therefore, our work offers a new strategy that is low cost and highly efficient for large-scale fabrication of BNNTs, and demonstrates that the prepared BNNTs have great potential applications in thermal interface materials.