Understanding Controls on Interfacial Wetting at Epitaxial Graphene: Experiment and Theory

Abstract

The interaction of interfacial water with graphitic carbon at the atomic scale is studied as a function of the hydrophobicity of epitaxial graphene. High resolution X-ray reflectivity shows that the graphene-water contact angle is controlled by the average graphene thickness, due to the fraction of the film surface expressed as the epitaxial buffer layer whose contact angle (contact angle θ_c = 73°) is substantially smaller than that of multilayer graphene (θ_c = 93°). Classical and ab initio molecular dynamics simulations show that the reduced contact angle of the buffer layer is due to both its epitaxy with the SiC substrate and the presence of interfacial defects. This insight clarifies the relationship between interfacial water structure and hydrophobicity, in general, and suggests new routes to control interface properties of epitaxial graphene.

40 Pages, 3 Tables, 8 Figures; Some minor corrections and changes have been made through the publication production process. The manuscript has been published on-line by Physical Review B

References in corpus (10)

• Graphene: Status and Prospects
• Graphene: A sub-nanometer trans-electrode membrane
• Ab initio Study of Graphene on SiC
• Surface energy engineering of graphene
• Origins of anomalous electronic structures of epitaxial graphene on silicon carbide
• DNA-decorated graphene chemical sensors
• Imaging the interface of epitaxial graphene with silicon carbide via scanning tunneling microscopy
• Epitaxial graphene on SiC(0001): More than just honeycombs
• The interface structure of epitaxial graphene grown on 4H-SiC(0001)
• How water meets a very hydrophobic surface

Cited by in corpus (11)

• Aqueous Proton Transfer Across Single Layer Graphene
• Water on graphene: Review of recent progress
• Substrate-assisted nucleation of ultra-thin dielectric layers on graphene by atomic layer deposition
• Aqueous ion trapping and transport in graphene-embedded 18-crown-6 ether pores
• Molecular dynamics simulation of behaviour of water in nano-confined ionic liquid--water mixtures
• Atmospheric doping effects in epitaxial graphene: correlation of local and global electrical measurements
• Non-Reciprocal Interactions Induced by Water in Confinement
• Electrolyte solutions at curved electrodes. II. Microscopic approach
• Electrolyte solutions at curved electrodes. I. Mesoscopic approach
• Water desorption and re-adsorption on epitaxial graphene studied by SPM
• Trivalent ion overcharging on electrified graphene