Sun Zhenyu, Vivekananthan Jeevanthi, Guschin Dmitrii A, Huang Xing, Kuznetsov Volodymyr, Ebbinghaus Petra, Sarfraz Adnan, Muhler Martin, Schuhmann Wolfgang
Analytische Chemie-Elektroanalytik & Sensorik, Ruhr-Universität Bochum, 44780 Bochum (Germany); Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780 Bochum (Germany).
Chemistry. 2014 May 5;20(19):5752-61. doi: 10.1002/chem.201400098. Epub 2014 Mar 27.
Modified acrylate polymers are able to effectively exfoliate and stabilize pristine graphene nanosheets in aqueous media. Starting with pre-exfoliated graphite greatly promotes the exfoliation level. The graphene concentration is significantly increased up to 11 mg mL(-1) by vacuum evaporation of the solvent from the dispersions under ambient temperature. TEM shows that 75 % of the flakes have fewer than five layers with about 18 % of the flakes consisting of monolayers. Importantly, a successive centrifugation and redispersion strategy is developed to enable the formation of dispersions with exceptionally high graphene-to-stabilizer ratio. Characterization by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy shows the flakes to be of high quality with very low levels of defects. These dispersions can act as a scaffold for the immobilization of enzymes applied, for example, in glucose oxidation. The electrochemical current density was significantly enhanced to be approximately six times higher than an electrode in the absence of graphene, thus showing potential applications in enzymatic biofuel cells.
改性丙烯酸酯聚合物能够在水性介质中有效地剥离并稳定原始石墨烯纳米片。从预剥离的石墨开始极大地提高了剥离程度。通过在环境温度下从分散体中真空蒸发溶剂，石墨烯浓度显著提高至11 mg mL⁻¹。透射电子显微镜（TEM）显示，75%的薄片层数少于五层，约18%的薄片为单层。重要的是，开发了一种连续离心和再分散策略，以形成具有极高石墨烯与稳定剂比例的分散体。通过高分辨率透射电子显微镜、X射线光电子能谱、X射线衍射和拉曼光谱表征表明，这些薄片质量高，缺陷水平极低。这些分散体可作为固定化酶的支架，例如应用于葡萄糖氧化。电化学电流密度显著增强，比不存在石墨烯时的电极高出约六倍，从而显示出在酶促生物燃料电池中的潜在应用。
