Angelikopoulos Panagiotis, Bock Henry
Department of Chemical Engineering, Heriot-Watt University, Edinburgh, Scotland, UK.
J Phys Chem B. 2008 Nov 6;112(44):13793-801. doi: 10.1021/jp804891a. Epub 2008 Oct 15.
The self-assembly of surfactant molecules on crossing carbon nanotubes has been investigated using a bead-spring model and implicit solvent dissipative particle dynamics simulations. Adsorption is directed to the nanotube crossing by its higher hydrophobic potential which is due to the presence of two surfaces. As a consequence of the tendency of surfactant molecules to self-assemble into micelles, the adsorbed molecules form a "central aggregate" at the crossing, thus, confining the molecules to the immediate vicinity of the crossing. Adsorption on the remaining nanotube surface becomes significant only at higher surfactant concentrations, where the molecules self-assemble to hemimicelles which grow continuously to full micelles upon increase of the (bulk) surfactant concentration. Our results allow two conclusions for the rational design of nanostructured materials: (i) the size of the central aggregate can not be much larger than that of a bulk micelle and (ii) control of the adsorbed structures is conveniently possible via the (bulk) surfactant concentration.
使用珠簧模型和隐式溶剂耗散粒子动力学模拟研究了表面活性剂分子在交叉碳纳米管上的自组装。由于存在两个表面，吸附作用指向具有更高疏水势的纳米管交叉处。由于表面活性剂分子倾向于自组装成胶束，吸附的分子在交叉处形成“中心聚集体”，从而将分子限制在交叉处的紧邻区域。仅在较高的表面活性剂浓度下，剩余纳米管表面的吸附才变得显著，此时分子自组装成半胶束，随着（本体）表面活性剂浓度的增加，半胶束不断生长为完整的胶束。我们的结果为纳米结构材料的合理设计得出两个结论：（i）中心聚集体的尺寸不能比本体胶束大太多；（ii）通过（本体）表面活性剂浓度可以方便地控制吸附结构。
