Effect of Boron Nitride Concentration: Synthesis and Characterization of Boron Nitride Nanosheets (BNNSs) Exfoliated in Water

Abstract

While layered nanomaterials or twodimensional nanomaterials are defined as materials with relatively large lateral dimensions and strong chemical bonds, the ability to form less layered and weaker Van der Waal bonds is an active research area. Hexagonal boron nitride (h-BN) is still one of the two-dimensional nanomaterials whose research is continuing1. So far, several methods for synthesizing 2D h-BN have been developed. Similar to graphene, 2D h-BN can be produced by mechanical or chemical exfoliation. The methods of producing boron nitride nanosheets (BNNSs) are generally those which can be classified as a bottomup approach that forms a two-dimensional nanosheet by incorporating small molecules or precursors into complex nanostructures. In contrast, the exfoliation approach creates a 2D nanosheet starting from bulk materials that can be classified as a top down method2. In a study conducted by Wang et al. boron nitride nanosheets were produced by exfoliation on a large scale in methane sulfonic acid. BNNSs were produced for the first time by liquid phase exfoliation of h-BN particles in methane sulfonic acid. Researchers have reported that such sulfonic acid is more potent against exfoliation and stabilization of BNNS compared to commonly used organic solvents. They concluded that the yield of the product in methane sulfonic acid solution could reach up to 0.3 mg/mL3. Zhi and colleagues in their study have made large-scale synthesis of BNNSs. N, Ndimethylformamide (DMF), a strong polar solvent, was used. The researchers increased the mechanical strength of composites by 22% by using BNNSs in composite production4. In this study, BNNSs were prepared at different concentrations and various characterization procedures were performed. Boron nitride powder (micron size,> 98% purity, Bortek Bor Teknolojileri ve Mekatronik San. Tic. A.Ş.) was used to form BNNSs. Deionized water was used as solvent in the preparation of the suspension. Sodium dodecyl sulfate (SDS, Sigma Aldrich, 98.5%) was used as the surface activator to ensure effective distribution of boron nitride in water. Boron nitride nanosheets were synthesized by a method known as liquid exfoliation. In Figure 1 schematic diagram of BNNSs synthesis were given.