Formation of Two-Dimensional Micelles on Graphene: Multi-Scale Theoretical and Experimental Study

Robinson, Benjamin J.; Bailey, Steven W.D.; O’Driscoll, Luke J.; Visontai, David; Welsh, Daniel J.; Mostert, Albertus B.; Mazzocco, Riccardo; Rabot, Caroline; Jarvis, Samuel P.; Kolosov, Oleg V.; Bryce, Martin R.; Lambert, Colin

Abstract

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.

Citation

Robinson, B. J., Bailey, S. W., O’Driscoll, L. J., Visontai, D., Welsh, D. J., Mostert, A. B., …Lambert, C. (2017). Formation of Two-Dimensional Micelles on Graphene: Multi-Scale Theoretical and Experimental Study. ACS Nano, 11(3), 3404-3412. https://doi.org/10.1021/acsnano.7b01071

• Journal Article Type: Article
• Acceptance Date: Mar 10, 2017
• Online Publication Date: Mar 10, 2017
• Publication Date: Mar 28, 2017
• Deposit Date: Apr 4, 2017
• Publicly Available Date: Apr 5, 2017
• Journal: ACS Nano
• Print ISSN: 1936-0851
• Electronic ISSN: 1936-086X
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 3
• Pages: 3404-3412
• DOI: https://doi.org/10.1021/acsnano.7b01071
• Public URL: https://durham-repository.worktribe.com/output/1389814