| Autor: |
Benjamin J, Robinson, Steven W D, Bailey, Luke J, O'Driscoll, David, Visontai, Daniel J, Welsh, Albertus B, Mostert, Riccardo, Mazzocco, Caroline, Rabot, Samuel P, Jarvis, Oleg V, Kolosov, Martin R, Bryce, Colin, Lambert |
| Rok vydání: |
2017 |
| Zdroj: |
ACS nano. 11(3) |
| ISSN: |
1936-086X |
| Popis: |
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-oligoethylene 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. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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