The University of Oklahoma, School of Chemical, Biological, and Materials Engineering and Institute for Applied Surfactant Research, Norman, OK 73019, USA.
Phys Chem Chem Phys. 2010 Oct 28;12(40):13137-43. doi: 10.1039/c0cp00600a. Epub 2010 Sep 13.
The structure of aqueous sodium dodecyl sulfate (SDS) surfactant aggregates formed on small graphene sheets and graphene nanoribbons has been studied using all-atom molecular dynamics simulations. Because the edges of the carbonaceous supports confine laterally the surfactant aggregates, by changing the size of the support (diameter of graphene sheets and width of graphene nanoribbons) it is possible to investigate lateral confinement effects on the aggregate morphology. The results are compared to those available on graphite, with no lateral confinement. Aqueous SDS aggregates were studied on 2.0 nm, 5.0 nm, and 10.0 nm circular graphene sheets and on 2.0 and 5.0 nm wide graphene nanoribbons. For the first time our results show that, because of lateral confinement provided by the graphene edges, SDS yields multiple layers, hemispheres, hemicylinders or multiple hemispheres depending on the graphene size and shape. Results are quantified in terms of morphology of the surfactant aggregates, order parameter of the adsorbed surfactant aggregates, and number of water molecules at contact with the carbonaceous support.
使用全原子分子动力学模拟研究了在小石墨烯片和石墨烯纳米带表面形成的十二烷基硫酸钠（SDS）表面活性剂聚集体的结构。由于碳质载体的边缘限制了表面活性剂聚集体的横向，因此通过改变载体的尺寸（石墨烯片的直径和石墨烯纳米带的宽度）可以研究横向对聚集体形态的限制作用。将结果与无横向限制的石墨的结果进行了比较。在 2.0nm、5.0nm 和 10.0nm 的圆形石墨烯片以及 2.0nm 和 5.0nm 宽的石墨烯纳米带表面上研究了水溶液中的 SDS 聚集体。我们的研究结果首次表明，由于石墨烯边缘提供的横向限制，SDS 会产生多层、半球、半圆柱或多个半球，具体取决于石墨烯的尺寸和形状。通过表面活性剂聚集体的形态、吸附表面活性剂聚集体的有序参数以及与碳质载体接触的水分子数量来定量表示结果。
