Department of Applied Chemistry, Yuncheng University, Yuncheng 044000, People's Republic of China.
ACS Appl Mater Interfaces. 2013 Jun 12;5(11):4843-55. doi: 10.1021/am400582n. Epub 2013 May 16.
Stable Pickering emulsions were prepared using only graphene oxide (GO) as a stabilizer, and the effects of the type of oil, the sonication time, the GO concentration, the oil/water ratio, and the pH value on the stability, type, and morphology of these emulsions were investigated. In addition, the effects of salt and the extent of GO reduction on emulsion formation and stability were studied and discussed. The average droplet size decreased with sonication time and with GO concentration, and the emulsions tended to achieve good stability at intermediate oil/water ratios and at low pH values. In all solvents, the emulsions were of the oil-in-water type, but interestingly, some water-in-oil-in-water (w/o/w) multiple emulsion droplets were also observed with low GO concentrations, low pH values, high oil/water ratios, high salt concentrations, or moderately reduced GO in the benzyl chloride-water system. A Pickering emulsion stabilized by Ag/GO was also prepared, and its catalytic performance for the reduction of 4-nitrophenol was investigated. This research paves the way for the fabrication of graphene-based functional materials with novel nanostructures and microstructures.
采用氧化石墨烯（GO）作为唯一稳定剂制备了稳定的 Pickering 乳液，并考察了油的种类、超声时间、GO 浓度、油/水比和 pH 值对乳液稳定性、类型和形态的影响。此外，还研究和讨论了盐和 GO 还原程度对乳液形成和稳定性的影响。平均液滴尺寸随超声时间和 GO 浓度的增加而减小，乳液在中间油/水比和低 pH 值下趋于达到良好的稳定性。在所有溶剂中，乳液均为油包水型，但有趣的是，在低 GO 浓度、低 pH 值、高油/水比、高盐浓度或适度还原的 GO 存在下，在苯甲酰氯-水中体系中也观察到了一些水包油包水（w/o/w）多重乳液液滴。还制备了由 Ag/GO 稳定的 Pickering 乳液，并研究了其对 4-硝基苯酚还原的催化性能。这项研究为制备具有新型纳米结构和微结构的基于石墨烯的功能材料铺平了道路。
