School of Materials Science and Engineering Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Small. 2010 Mar 8;6(5):663-9. doi: 10.1002/smll.200902221.
Conjugated-polyelectrolyte (CPE)-functionalized reduced graphene oxide (rGO) sheets are synthesized for the first time by taking advantage of a specially designed CPE, PFVSO(3), with a planar backbone and charged sulfonate and oligo(ethylene glycol) side chains to assist the hydrazine-mediated reduction of graphene oxide (GO) in aqueous solution. The resulting CPE-functionalized rGO (PFVSO(3)-rGO) shows excellent solubility and stability in a variety of polar solvents, including water, ethanol, methanol, dimethyl sulfoxide, and dimethyl formamide. The morphology of PFVSO(3)-rGO is studied by atomic force microscopy, X-ray diffraction, and transmission electron microscopy, which reveal a sandwich-like nanostructure. Within this nanostructure, the backbones of PFVSO(3) stack onto the basal plane of rGO sheets via strong pi-pi interactions, while the charged hydrophilic side chains of PFVSO(3) prevent the rGO sheets from aggregating via electrostatic and steric repulsions, thus leading to the solubility and stability of PFVSO(3)-rGO in polar solvents. Optoelectronic studies show that the presence of PFVSO(3) within rGO induces photoinduced charge transfer and p-doping of rGO. As a result, the electrical conductivity of PFVSO(3)-rGO is not only much better than that of GO, but also than that of the unmodified rGO.
首次利用具有平面骨架和带电磺酸盐及聚（乙二醇）侧链的特殊设计的共轭聚电解质 PFVSO(3)，通过水合肼介导的氧化石墨烯（GO）在水溶液中的还原反应，合成了共轭聚电解质功能化还原氧化石墨烯（PFVSO(3)-rGO）。所得的 PFVSO(3)-rGO 在多种极性溶剂中，包括水、乙醇、甲醇、二甲基亚砜和二甲基甲酰胺中具有优异的溶解性和稳定性。原子力显微镜、X 射线衍射和透射电子显微镜研究了 PFVSO(3)-rGO 的形态，揭示了三明治状的纳米结构。在这种纳米结构中，PFVSO(3)的骨架通过强π-π相互作用堆叠在 rGO 片的基面之上，而 PFVSO(3)的带电亲水性侧链通过静电和空间排斥作用防止 rGO 片聚集，从而使 PFVSO(3)-rGO 在极性溶剂中具有溶解性和稳定性。光电研究表明，PFVSO(3)在 rGO 中的存在诱导了光致电荷转移和 rGO 的 p 掺杂。结果，PFVSO(3)-rGO 的电导率不仅远优于 GO，而且优于未改性的 rGO。
