Dibromocarbene Functionalization of Boron Nitride Nanosheets: Toward Band Gap Manipulation and Nanocomposite Applications

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• 作者：Toby Sainsbury ; Arlene O鈥橬eill ; Melissa K. Passarelli ; Maud Seraffon ; Dipak Gohil ; Sam Gnaniah ; Steve J. Spencer ; Alasdair Rae ; Jonathan N. Coleman
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：December 23, 2014
• 年：2014
• 卷：26
• 期：24
• 页码：7039-7050
• 全文大小：614K
• ISSN：1520-5002

文摘

We report the covalent functionalization of exfoliated boron nitride nanosheets (BNNSs) using dibromocarbene (DBC) species. The functionalization of BNNSs is enabled as the nanosheets are utilized as two-dimensional phase-transfer catalysts for the migration of carbenes across the organic鈥揳queous phase boundary. We postulate that BNNSs stabilize carbenes by forming B-CBr₂ ylides and in turn act as the reaction substrate. DBC functionalization of BNNSs results in the formation of B鈥揅 and B鈥揘 bonds to the sp²-hybridized BNNS lattice via the formation of dibromo-bridged bicyclo BCN systems. The covalent functionalization was characterized using HR-TEM, AFM, EELS, XRD, EDX, ToF-SIMS, TGA, Raman, XPS, FTIR, and UV鈥搗is techniques. Utilization of CBr₂ groups as a means by which BNNSs may be integrated and interfaced with solvents, molecular species, and condensed-phase materials was demonstrated by grafting alkyl chains from the functional groups via alkyl/halogen exchange. Alkyl-functionalized BNNSs were integrated within polyethylene (LDPE) and extruded to form BNNS-nanocomposite fibers. Implications of the covalent functionalization of h-BN are considered in the context of band gap manipulation and the versatility of the CBr₂ functional groups to enable subsequent chemical derivatization.