Green Production of Covalently Functionalized Boron Nitride Nanosheets via Saccharide-Assisted Mechanochemical Exfoliation

Hexagon boron nitride (BN) has evolved into a quite competitive building block in electrical and electronic fields. However, exfoliation and functionalization of BN nanosheets (BNNSs) confront a formidable challenge. Herein, an effective and green saccharide-assisted mechanochemical approach was proposed to exfoliate and synchronously functionalize BNNSs. The production yield of BNNSs exhibited a notable enhancement by incorporating saccharides, where the highest yield was up to ∼29.4% with the assistance of glucose. The saccharides enhanced the applied force of ball milling to promote BN delamination. The exfoliated cost is much lower for our proposed approach than for the previously reported exfoliation methods. The theoretical first-principle calculation and experimental results confirmed that the obtained BNNSs (saccharide-g-BNNSs) remained intact and were covalently grafted with saccharides in different degrees. Benefitting from the outstanding comprehensive properties of saccharide-g-BNNSs, their gelatin composite films exhibited multifunctional performance, such as high/anisotropic thermal conductivity, shielding deep blue to the UV light, and flame retardance. Our work paves a promising way to greenly prepare few-layered and functionalized BNNSs and to expedite their applications.