Water confined between adjoining hydrophobic and hydrophilic surfaces (a Janus interface) is found to form stable films of nanometer thickness whose responses to shear deformations are extraordinarily noisy. The power spectrum of this noise is quantified. In addition, the frequency dependence of the complex shear modulus is a power law with slope one-half, indicating a distribution of relaxatio...

It has been recognized well that it is necessary to achieve superhydrophobic surfaces on intrinsically hydrophobic materials. However, recently experiments have demonstrated that it is possible to fabricate superhydrophobic surfaces on intrinsically hydrophilic materials by creating adequate roughness. In this study, such a possibility for superhydrophobicity on a hydrophilic surface with an in...

We perform systematic molecular dynamics simulations of water confined between two nanoscale plates at T = 300K. We investigate the effect of pressure (-0.15 GPa< or = P< or =0.2GPa) and plate separation (0.4 nm < or =d < or =1.6 nm) on the phase behavior of water when the plates are either hydrophobic or hydrophilic. When water is confined between hydrophobic plates, capillary evaporation occu...

The properties of nanoconfined and interfacial water in the proximity of hydrophobic surfaces play a pivotal role in a variety of important phenomena such as protein folding. Water inside single-walled carbon nanotubes (SWNTs) can provide an ideal system for investigating such nanoconfined interfacial water on hydrophobic surfaces, provided that the nanotubes can be opened without introducing e...

The friction between a single silica glass sphere and a flat silica glass surface has been investigated using lateral force microscopy. Two types of silica surface were investigated, one fully hydroxylated and the other partially dehydroxlated. These samples have markedly different wetting properties and are known as hydrophilic and hydrophobic silica, respectively. The lateral friction force a...

Water conformation around hydrophobic side chains of four amino acids (glycine, L-alanine, L-aminobutyric acid, and L-norvaline) was investigated via changes in complex dielectric constant in the terahertz (THz) region. Each of these amino acids has the same hydrophilic backbone, with successive additions of hydrophobic straight methylene groups (-CH2-) to the side chain. Changes in the degree ...

Direct and simultaneous measurements of the normal and lateral forces encountered by a nanosize spherical silicon tip approaching a solid surface in purified water are reported. For tip-surface distances, 0±0.03 nm d 2 nm, experiments and grand canonical molecular-dynamics simulations find oscillatory solvation forces for hydrophilic surfaces, mica and glass, and less pronounced oscillations fo...