Structured and viscous water in subnanometer gaps
نویسندگان
چکیده
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 for a hydrophobic surface, graphite. The simulations reveal layering of the confined water density and the development of hexagonal order in layers proximal to a quartz surface. For subnanometer hydrophilic confinement, the lateral force measurements show orders of magnitude increase of the viscosity with respect to bulk water, agreeing with a simulated sharp decrease in the diffusion constant. No viscosity increase is observed for hydrophobic surfaces.
منابع مشابه
Coexistence of classical and quantum plasmonics in large plasmonic structures with subnanometer gaps
متن کامل
Viscous Dissipation Impact on Free Convection Flow of Cu-water Nanofluid in a Circular Enclosure with Porosity Considering Internal Heat Source
In this work, free convection of Cu-water nanofluid in an enclosure by considering internally heat generated in the porous circular cavity and the impacts of viscous dissipation are numerically evaluated by control volume finite element method (CVFEM). The outer and inner sides of the circular porous enclosure are maintained at a fixed temperature while insulating the other two walls. The impac...
متن کاملRegenerable Subnanometer Pd Clusters on Zirconia for Highly Selective Hydrogenation of Biomass-Derived Succinic Acid in Water
The size of metal particles is an important factor to determine the performance of the supported metal catalysts. In this work, we report subnanometer Pd clusters supported on zirconia by the microwave-assisted hydrothermal method. The presence of subnanometer Pd clusters on the zirconia surface was confirmed by two-dimensional Gaussian-function fits of the aberration-corrected high-angle annua...
متن کاملViscous Models Comparison in Water Impact of Twin 2D Falling Wedges Simulation by Different Numerical Solvers
In this paper, symmetric water entry of twin wedges is investigated for deadrise angle of 30 degree. Three numerical simulation of a symmetric impact, considering rigid body dynamic equations of motion in two-phase flow is presented. The two-phase flow around the wedges is solved by Finite Element based on Finite Volume method (FEM-FVM) which is used in conjunction with Volume of Fluid (VOF) sc...
متن کاملThe Performance Evaluation of Viscous-Modified Surfactant Water Flooding in Heavy Oil Reservoirs at Varying Salinity of Injected Polymer-Contained Surfactant Solution
This study examines the effects of change in the concentrations of monovalent and divalent ions in the polymer-contained surfactant solution on the macroscopic behavior of viscous-modified surfactant waterflooding in heavy oil reservoirs. Salts that are used in this set of floods were sodium chloride, magnesium chloride, and calcium chloride. The results indicate that four different ranges ...
متن کامل