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

Abstract

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.

Highly and Uniformly Thermal Conductive Phase Change Composites by Constructing the Bidirectionally Oriented and Interconnected Boron Nitride Nanosheet Network

“…Thin and functionalized BNNSs serving as structural bases are first obtained via green glucose-assisted ball milling exfoliation (Figure S1). − To ameliorate the dispersibility of BNNSs, poly­(vinyl alcohol) (PVA) is employed as the dispersing agent to ensure good stability of the BNNS aqueous dispersion during the subsequent network formation. As freezing proceeds, dual orthogonal temperature gradients are exerted, benefiting from the slow heat transfer of the bottom poly­(dimethylsiloxane) (PDMS) wedge, forcing the ice crystals to grow preferentially from the edge to the center and the bottom to the top at the same time.…”

2D Boron Nitride Nanosheets for Smart Thermal Management and Advanced Dielectrics

“…Ball milling, as a most common approach of mechanically exfoliating bulk 2D materials (e.g., hBN), exhibits some advantages including environmentally friendly, simple to operate and easy to realize industrial production, and then has been attracted wide attentions from academic and industry. [21,29,[53][54][55][56][57][58][59] As reported by Li et al, [53] who adopted the low-energy ball milling with the aid of milling agent to successfully produce the BNNS under the pure nitrogen gas pressure of 200 KPa. The produced BNNS shows not only a lateral dimension of ≈250 nm and thicknesses of <10 layers but also a very small amount of point defects or impurities, and the production yield can reach 67%.…”

Cellulose nanocrystal synergistically enhanced polyurethane composites via fish‐net microstructure: Light shielding and mechanical properties

“…And then weak or no light absorption for light absorbents occurred when the composites exposed to UV light, bring about poor UV‐light shielding. Accordingly, some functional efforts had been made to improve this problem, such as covalent or noncovalent modification with silane, amphiphilic polymer, hydrophilic curing agent or cinnamic acid 25–27 . Furthermore, Incorporation of some organic dyes as UV absorbents into polymer matrices was also the potential strategy to endow light shielding properties.…”

“…Accordingly, some functional efforts had been made to improve this problem, such as covalent or noncovalent modification with silane, amphiphilic polymer, hydrophilic curing agent or cinnamic acid. [25][26][27] Furthermore, Incorporation of some organic dyes as UV absorbents into polymer matrices was also the potential strategy to endow light shielding properties. For example, incorporating graphene or graphene oxide (GO) into polymer matrices prevented UV light in 290-320 nm range.…”