Structure and Depletion at Fluoro- and Hydro-carbon/Water Liquid/Liquid Interfaces

Density depletion and enhanced fluctuations in water near hydrophobic solutes: identifying the underlying physics

We investigate the origin of the density depletion and enhanced density fluctuations that occur in water in the vicinity of an extended hydrophobic solute. We argue that both phenomena are remnants of the critical drying surface phase transition that occurs at liquid-vapor coexistence in the macroscopic planar limit, ie. as the solute radius $R_s\to\infty$. Focusing on the density profile $ρ(r)$ and a sensitive spatial measure of fluctuations, the local compressibility profile $χ(r)$, we develop a scaling theory which expresses the extent of the density depletion and enhancement in compressibi…

流体力和耗尽相互作用在疏水表面上引导水相金纳米棒组装中的作用

Role of Fluid Forces and Depletion Interactions in Directing Assembly of Aqueous Gold Nanorods on Hydrophobic Surfaces

本研究通过关联原位干燥轮廓与沉积图案，揭示了流体力和耗尽相互作用在金纳米棒蒸发自组装中的作用，为纳米材料结构控制提供框架。

The search for Nanobubbles by using specular and off-specular Neutron Reflectometry

We apply specular and off-specular neutron reflection at the hydrophobic silicon/water interface to check for evidence of nanoscopic air bubbles whose presence is claimed after an ad hoc procedure of solvent exchange. Nanobubbles and/or a depletion layer at the hydrophobic/water interface have long been discussed and generated a plethora of controversial scientific results. By combining neutron reflectometry (NR), off-specular reflectometry (OSS) and grazing incidence small angle neutron scattering (GISANS), we studied the interface between hydrophobized silicon and heavy water before and afte…

孤立游动细胞因局部液体耗尽而无法移动

Immobility of isolated swarmer cells due to local liquid depletion

针对细菌群游中孤立细胞不移动而细胞簇可移动的现象，本研究揭示低局部细胞密度下孤立细胞暂时无法移动与局部液体耗尽及鞭毛束散开相关，指出忽略流体动力学效应的干模型不足以描述群游细菌。

Water in nanopores. II. Liquid-vapour phase transition near hydrophobic surfaces

The liquid-vapour phase transition near a weakly attractive surface is studied by simulations of the coexistence curves of water in hydrophobic pores. There is a pronounced gradual density depletion of the liquid phase near the surface without any trend to the formation of a vapour layer below the bulk critical temperature Tc. The temperature dependence of the order parameter in the surface layer follows the power law (rol - rov) ~ (1 - T/Tc)^beta1 with a value of the exponent beta1 close to the critical exponent beta1 = 0.82 of the ordinary transition in the Ising model. The order parameter p…

Competition of hydrophobic and Coulombic interactions between nano-sized solutes

The solvation of charged, nanometer-sized spherical solutes in water, and the effective, solvent-induced force between two such solutes are investigated by constant temperature and pressure Molecular Dynamics simulations of model solutes carrying various charge patterns. The results for neutral solutes agree well with earlier findings, and with predictions of simple macroscopic considerations: substantial hydrophobic attraction may be traced back to strong depletion (``drying'') of the solvent between the solutes. This hydrophobic attraction is strongly reduced when the solutes are uniformly c…