title: Water at hydrophobic substrates: curvature, pressure, and temperature effects.
abstract: We studied the water density profile close to spherical and planar hydrophobic objects using molecular dynamics (MD) simulations. For normal pressure and room temperature, the depletion layer thickness of a planar substrate is approximately 2.5 Angstroms. Even for quite large spherical solutes with a radius of R = 18 Angstroms, the depletion layer thickness is reduced by 30%, which shows that substrate curvature and roughness is an experimentally important factor. Rising temperature leads to a substantial increase of the depletion layer thickness. The compressibility of the depletion layer is found to be surprisingly small and only approximately 5 times higher than that of bulk water. A high electrostatic surface potential of 0.5 V is found, which presumably plays an important role in the presence of charged solutes, since it can promote adsorption into the interfacial layer.
authors.affiliation: Heat Physics Department of Uzbekistan Academy of Sciences, 28 Katartalstr., 700135 Tashkent, Uzbekistan.
authors.forename: Shavkat I
authors.initials: SI
authors.lastname: Mamatkulov
authors.forename: Pulat K
authors.initials: PK
authors.lastname: Khabibullaev
authors.forename: Roland R
authors.initials: RR
authors.lastname: Netz