Zu Sheng-Zhen, Zhou Ding, Han Bao-Hang
National Center for Nanoscience and Technology, Beijing 100190, China.
J Nanosci Nanotechnol. 2013 Feb;13(2):946-53. doi: 10.1166/jnn.2013.6007.
Graphene sheets have been dispersed in water and organic solvents by noncovalent surface modification with the assistance of bifunctional molecule pyrene-adamantane (Py-Ad) carrying a pyrene moiety. Lipophilic graphene sheets have been obtained in the form of graphene-Py-Ad in a wide variety of organic solvents, such as dimethyl sulfoxide, N-methyl-2-pyrrolidone, N,N'-dimethylformamide, and tetrahydrofuran, in which the adamantane moieties served as the three-dimensional steric groups keeping the graphene sheets from stacking. Supramolecular complexes were employed as the dispersing agent for graphene formed through in situ reduction by hydrazine or hydroquinone. Water-dispersible graphene sheets have been obtained in the form of graphene-Py-Ad-bMCD (methylated beta-cyclodextrin, bMCD), in which the pyrene moiety attached to graphene by pi-pi stacking interaction and hydrophobic effect, and the adamantane group formed complex with bMCD, yielding a supramolecular system that made graphene sheets dissolved in water through the formed hydrophilic cyclodextrin shell. The resulting supramolecular complexes were characterized by atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, thermal gravimetric analysis, transmission electron microscopy, ultraviolet-visible spectroscopy, fluorescence spectroscopy, and Raman spectroscopy.
通过携带芘基团的双功能分子芘 - 金刚烷（Py - Ad）的辅助非共价表面改性，石墨烯片已分散在水和有机溶剂中。在多种有机溶剂中，如二甲基亚砜、N - 甲基 - 2 - 吡咯烷酮、N，N'-二甲基甲酰胺和四氢呋喃，以石墨烯 - Py - Ad的形式获得了亲脂性石墨烯片，其中金刚烷部分作为三维空间基团防止石墨烯片堆叠。超分子配合物被用作通过肼或对苯二酚原位还原形成的石墨烯的分散剂。以石墨烯 - Py - Ad - bMCD（甲基化β - 环糊精，bMCD）的形式获得了水分散性石墨烯片，其中芘基团通过π - π堆积相互作用和疏水作用附着在石墨烯上，金刚烷基团与bMCD形成配合物，产生一个超分子体系，该体系通过形成的亲水性环糊精壳使石墨烯片溶解在水中。通过原子力显微镜、X射线光电子能谱、X射线衍射、热重分析、透射电子显微镜、紫外 - 可见光谱、荧光光谱和拉曼光谱对所得超分子配合物进行了表征。
