Dual Functionalization of Hexagonal Boron Nitride Nanosheets Using Pyrene-Tethered Poly(4-vinylpyridine) for Stable Dispersion and Facile Device Incorporation

Owing to its favorable solution processability, the development of a stable dispersion of two-dimensional (2D) boron nitride (BN) has received significant attention for cutting-edge optic/electronic applications. Herein, we report an efficient method to disperse BN nanosheets (BNNSs) in polar solvents via dual noncovalent interactions using pyrene-tethered poly(4-vinylpyridine) (P4VP-Py). As a dispersion agent, P4VP-Py enables bifunctionalization with BNNS through π–π and Lewis acid–base interactions arising from the pyrene and pyridine moiety, respectively, resulting in highly stable BNNS dispersions in different polar solvents. The blend of P4VP-Py-functionalized BNNS with the pristine P4VP matrix resulted in increased thermal conductivity and dielectric constant combined with superior thermal stability by forming a compatible interface between the P4VP-Py matrix and the BNNS adjacent to the P4VP-Py. We demonstrated that dual noncovalent functionalization of BNNSs based on molecular design presents a strategy to achieve high dispersion of 2D materials into various media, ranging from polar solvents to solid matrices, for the expansion of advanced optic/electronic applications using BNNSs.