Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Surface and interfacial interactions of multilayer graphitic structures with local environment
AU - Mazzocco, Riccardo
AU - Robinson, Benjamin
AU - Rabot, Caroline
AU - Delamoreanu, A.
AU - Zenasni, Aziz
AU - Dickinson, James
AU - Boxall, Colin
AU - Kolosov, Oleg
PY - 2015/6/30
Y1 - 2015/6/30
N2 - In order to exploit the potential of graphene in next-generation devices, such as supercapacitors, rechargeable batteries, displays and ultrathin sensors, it is crucial to understand the solvent interactions with the graphene surface and interlayers, especially where the latter may be in competition with the former, in the medium of application deployment. In this report, we combine quartz crystal microbalance (QCM) and ultrasonic force microscopy methods to investigate the changes in the film-substrate and film-environment interfaces of graphene and graphene oxide films, produced by diverse scalable routes, in both polar (deionised water) and non-polar (dodecane) liquid and vapour environments. In polar liquid environments, we observe nanobubble adsorption/desorption on the graphene film corresponding to a surface coverage of up to 20%. As no comparable behaviour is observed for non-polar environment, we conclude that nanobubble formation is directly due to the hydrophobic nature of graphene with direct consequences for electrode structures immersed in electrolyte solutions. The amount of water adsorbed by the graphene films was found to vary considerably from 0.012 monolayers of water per monolayer of reduced graphene oxide to 0.231 monolayers of water per monolayer of carbon diffusion growth graphene. This is supported by direct nanomechanical mapping of the films immersed in water where an increased variation of local stiffness suggests water propagation within the film and/or between the film and substrate. Film thickness calculations performed for QCM, atomic force microscopy topography, Raman spectroscopy and optical transmission measurements, show that due to the turbostratic structures of large area films Raman returns results an order of magnitude lower (1-2 graphene layers) than direct measurement by QCM (46 ± 1 layers).
AB - In order to exploit the potential of graphene in next-generation devices, such as supercapacitors, rechargeable batteries, displays and ultrathin sensors, it is crucial to understand the solvent interactions with the graphene surface and interlayers, especially where the latter may be in competition with the former, in the medium of application deployment. In this report, we combine quartz crystal microbalance (QCM) and ultrasonic force microscopy methods to investigate the changes in the film-substrate and film-environment interfaces of graphene and graphene oxide films, produced by diverse scalable routes, in both polar (deionised water) and non-polar (dodecane) liquid and vapour environments. In polar liquid environments, we observe nanobubble adsorption/desorption on the graphene film corresponding to a surface coverage of up to 20%. As no comparable behaviour is observed for non-polar environment, we conclude that nanobubble formation is directly due to the hydrophobic nature of graphene with direct consequences for electrode structures immersed in electrolyte solutions. The amount of water adsorbed by the graphene films was found to vary considerably from 0.012 monolayers of water per monolayer of reduced graphene oxide to 0.231 monolayers of water per monolayer of carbon diffusion growth graphene. This is supported by direct nanomechanical mapping of the films immersed in water where an increased variation of local stiffness suggests water propagation within the film and/or between the film and substrate. Film thickness calculations performed for QCM, atomic force microscopy topography, Raman spectroscopy and optical transmission measurements, show that due to the turbostratic structures of large area films Raman returns results an order of magnitude lower (1-2 graphene layers) than direct measurement by QCM (46 ± 1 layers).
KW - Graphene
KW - thickness measurement
KW - segregation
KW - chemical reduction
KW - Atomic Force Microscopy
KW - Ultrasonic Force Microscopy
U2 - 10.1016/j.tsf.2015.04.016
DO - 10.1016/j.tsf.2015.04.016
M3 - Journal article
VL - 585
SP - 31
EP - 39
JO - Thin Solid Films
JF - Thin Solid Films
SN - 0040-6090
ER -