Liquid-Phase Exfoliation of Hexagonal Boron Nitride into Boron Nitride Nanosheets in Common Organic Solvents with Hyperbranched Polyethylene as Stabilizer

Large-scale production of boron nitride nanosheets (BNNSs) is of significant importance for their various applications. Herein, a facile strategy is well demonstrated for BNNS fabrication via liquid-phase exfoliation of bulk hexagonal boron nitride (h-BN) in common organic solvents with hyperbranched polyethylene (HBPE) as stabilizer. Synthesized from commercially abundant ethylene stock via a simple process, the HBPE is found to effectively promote h-BN exfoliation both in tetrahydrofuran and chloroform under sonication, to render stable dispersions of high-quality monolayer or few-layer BNNSs with adjustable concentrations. This has been confirmed to originate from the noncovalent CH- interactions between the HBPE and BNNS surface, which results in irreversible HBPE adsorption on the latter to effectively prevent their reaggregation. The resultant HBPE-functionalized BNNSs are highly dispersible in chloroform or N,N-dimethylformamide at a concentration as high as 10.0 mg mL(-1), and can be successfully used as nanofiller for a fluorinated copolymer.