• 文献标题:   Formation of Two-Dimensional Micelles on Graphene: Multi-Scale Theoretical and Experimental Study
  • 文献类型:   Article
  • 作  者:   ROBINSON BJ, BAILEY SWD, O DRISCOLL LJ, VISONTAI D, WELSH DJ, MOSTERT AB, MAZZOCCO R, RABOT C, JARVIS SP, KOLOSOV OV, BRYCE MR, LAMBERT C
  • 作者关键词:   2d micelle, surfactant, graphene, scanning probe microscopy, molecular dynamic
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Univ Lancaster
  • 被引频次:   5
  • DOI:   10.1021/acsnano.7b01071
  • 出版年:   2017

▎ 摘  要

Graphene and related two-dimensional (2D) materials possess outstanding electronic and mechanical properties, chemical stability, and high surface area. However, to realize graphene's potential for a range of applications in materials science and nanotechnology there is a need to understand and control the interaction of graphene with tailored high-performance surfactants designed to facilitate the preparation, manipulation, and functionalization of new graphene systems. Here we report a combined experimental and theoretical study of the surface structure and dynamics on graphene of pyrene-oligo ethylene glycol (OEG)-based surfactants, which have previously been shown to disperse carbon nanotubes in water. Molecular self-assembly of the surfactants on graphitic surfaces is experimentally monitored and optimized using a graphene coated quartz crystal microbalance in ambient and vacuum environments. Real-space nanoscale resolution nanomechanical and topographical mapping of submonolayer surfactant coverage, using ultrasonic and atomic force microscopies both in ambient and ultrahigh vacuum, reveals complex, multilength-scale self-assembled structures. Molecular dynamics simulations show that at the nanoscale these structures, on atomically flat graphitic surfaces, are dependent upon the surfactant OEG chain length and are predicted to display a previously unseen class of 2D self-arranged "starfish" micelles (2DSMs). While three-dimensional micelles are well-known for their widespread uses ranging from microreactors to drug-delivery vehicles, these 2DSMs possess the highly desirable and tunable characteristics of high surface affinity coupled with unimpeded mobility, opening up strategies for processing and functionalizing 2D materials.