Department of Chemical Engineering, Kyung Hee University, Yongin, Kyunggi-Do 336-701, South Korea.
J Colloid Interface Sci. 2013 Jul 1;401:148-54. doi: 10.1016/j.jcis.2013.02.054. Epub 2013 Apr 4.
Surface functionalization of graphene oxide (GO) an important graphene precursor using alkylamines of varying chain lengths followed by thermal treatment resulted in the formation of superhydrophobic surfaces. Alkylamines consisting of hydrophobic long chain alkyl groups and hydrophilic amine groups were chemically reacted to the GO surface via two types of reactions viz. (i) amidation reaction between amine groups and carboxylic acid sites of GO and (ii) nucleophilic substitution reactions between amine and epoxy groups on GO surface. Successful grafting of alkylamines was confirmed using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1)H NMR), and thermogravimetric analysis (TGA). Alkylamine-modified GO surfaces showed enhanced roughness, and this effect was more pronounced with increasing amine chain length. Water contact angle measurements revealed that the hydrophobic nature of graphene depended on the chain length of the grafted alkylamines, and this fact may be corroborated to the decrease in the surface energy values. Our results indicate that superhydrophobic graphene films can be produced by thermal treatment of hexadecylamine- and octadecylamine-grafted GO films. These results will provide valuable guidance for the design and manufacture of graphene-based biomaterials, medical instruments, structural composites, electronics, and renewable energy devices.
通过使用不同链长的烷基胺对氧化石墨烯（GO）进行表面功能化，这是一种重要的石墨烯前体，随后进行热处理，从而形成超疏水表面。烷基胺由疏水性长链烷基基团和亲水性胺基团组成，通过两种类型的反应化学接枝到 GO 表面：（i）胺基团和 GO 上的羧酸位点之间的酰胺反应，和（ii）GO 表面上的胺和环氧基团之间的亲核取代反应。成功接枝烷基胺可使用傅里叶变换红外光谱（FT-IR）、核磁共振（1H NMR）和热重分析（TGA）来确认。烷基胺修饰的 GO 表面显示出增强的粗糙度，并且随着胺链长度的增加，这种效果更加明显。水接触角测量表明，石墨烯的疏水性取决于接枝的烷基胺的链长，这一事实可能与表面能值的降低有关。我们的结果表明，通过对十六烷基胺和十八烷基胺接枝的 GO 薄膜进行热处理，可以制备出超疏水的石墨烯薄膜。这些结果将为基于石墨烯的生物材料、医疗器械、结构复合材料、电子和可再生能源设备的设计和制造提供有价值的指导。
