What x rays can tell us about the interfacial profile of water near hydrophobic surfaces | |
Article | |
关键词: LIQUID-VAPOR INTERFACE; REFLECTIVITY MEASUREMENTS; CAPILLARY WAVES; DENSITY; SCATTERING; ROUGHNESS; DEPLETION; METALS; FORCE; LAYER; | |
DOI : 10.1103/PhysRevB.88.035431 | |
来源: SCIE |
【 摘 要 】
The free surface of water and the interface between water and a hydrophobic surface both have positive interface energies. The water density near a free surface drops below the bulk density, and thus it is expected that water near a hydrophobic surface will also show a density depletion. However, efforts by multiple groups to detect and characterize the predicted gap at water-hydrophobic interfaces have produced contradictory results. We have studied the interface between water and fluoroalkylsilane self-assembled monolayers using specular x-ray reflectivity and analyzed the parameter-space landscapes of the merit functions being minimized by data fitting. This analysis yields a better understanding of confidence intervals than the customary process of reporting a unique best fit. We conclude that there are unambiguous gaps at water-hydrophobic interfaces when the hydrophobic monolayer is more densely packed.
【 授权许可】
Free