Tunable Alkylation of White Graphene (Hexagonal Boron Nitride) Using Reductive Conditions
Tunable Alkylation of White Graphene (Hexagonal Boron Nitride) Using Reductive Conditions
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DOI：
10.1021/acs.jpcc.9b05416
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发表时间：
2019-08-15
影响因子：
3.7
通讯作者：
Marti, Angel A.
中科院分区：
文献类型：
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作者：
de los Reyes, Carlos A.;Hernandez, Katharyn;Marti, Angel A.
六方氮化硼（h-BN），也称为白色石墨烯，具有无与伦比的性能组合，包括上级机械强度、良好的导热性、宽带隙以及化学和热惰性。然而，由于其对化学改性的厌恶，其应用进展不如碳纳米材料。在这篇手稿中，我们展示了在强还原条件下（比卢普斯-伯奇条件）使用卤代烷对六方氮化硼的官能化。比卢普斯-伯奇反应的可调谐性通过用1-溴十二烷和不同当量的Li与BN烷基化六方氮化硼来证明。我们发现，使用1：20 BN/Li的比例产生最高的化学改性，如使用热重分析和傅里叶变换红外光谱所示，并通过X射线光电子能谱支持。功能化的h-BN（fh-BN）的成像显示，它的片材在异丙醇中比原始的h-BN，其显示高度堆叠的纳米结构更好地剥离。此外，带有烷基链赋予纳米片在非极性溶剂（如十二烷）中具有改善的润湿性，并允许形成疏水膜。
Hexagonal boron nitride (h-BN), also known as white graphene, presents an unparalleled combination of properties, including superior mechanical strength, good thermal conductivity, a wide band gap, and chemical and thermal inertness. However, because of its aversion to chemical modification, its applications have not progressed as much as those of carbon nanomaterials. In this manuscript, we show the functionalization of hexagonal boron nitride using alkyl halides in strongly reducing conditions (Billups-Birch conditions). The tunability of the Billups-Birch reaction is demonstrated by alkylating hexagonal boron nitride with 1-bromododecane and varying equivalents of Li to BN. We found that using a 1:20 BN/Li ratio yields the highest chemical modification, as demonstrated using thermogravimetric analysis and Fourier transform infrared spectroscopy, and supported by X-ray photoelectron spectroscopy. Imaging of the functionalized h-BN (fh-BN) revealed that its sheets exfoliate better in isopropanol than pristine h-BN, which displays highly stacked nanostructures. Moreover, bearing alkyl chains confers the nanosheets with improved dispersibility in nonpolar solvents, such as dodecane, and allows the formation of hydrophobic films.