Molecular-dynamics simulation of the effect of ions on a liquid-liquid interface for a partially miscible mixture.
نویسندگان
چکیده
Molecular-dynamics simulations were performed to model the effect of added salt ions on the liquid-liquid interface in a partially miscible system. Simulations of the interface between saturated phases of a model 1-hexanol+water system show a bilayer structure of 1-hexanol molecules at the interface with -OH heads of the first layer directed into the water phase and the opposite orientation for the second layer. The alignment of the polar -OH groups at the interface stabilizes a charge separation of sodium and chloride ions when salt is introduced into the aqueous phase, producing an electrical double layer. Chloride ions aggregate nearer the interface and sodium ions move toward the bulk water phase, consistent with the explanation that the -OH alignment presents a region of partial positive charges to which the hydrated chloride atoms are attracted. Ions near the interface were found to be less solvated than those in the bulk phase. An electric field was also applied to drive ions through the interface. Ions crossing the interface tended to shed water molecules as they entered the hexanol bilayer, leaving a trail of water molecules. Stabilization and facilitated transport of the ion by interactions with the second layer of hexanol molecules appeared to be an important step in the mechanism of sodium ion transport.
منابع مشابه
Numerical simulation of the fluid dynamics in a 3D spherical model of partially liquefied vitreous due to eye movements under planar interface conditions
Partially liquefied vitreous humor is a common physical and biochemical degenerative change in vitreous body which the liquid component gets separated from collagen fiber network and leads to form a region of liquefaction. The main objective of this research is to investigate how the oscillatory motions influence flow dynamics of partial vitreous liquefaction (PVL). So far computational fluid d...
متن کاملDiffusive Dynamicsof Binary Lennard-Jones Liquid in the Presence of Gold Nanoparticle: A Mode Coupling Theory Analysis
Molecular dynamics simulation has been performed to analyze the effect of the presence of gold nanoparticle on dynamics of Kob-Anderson binary Lennard-Jones (BLJ) mixture upon supercooling within the framework of the mode coupling theory of the dynamic glass transition. The presence of gold nanoparticle has a direct effect on the liquid structure and causes the peaks of the radial distribution ...
متن کاملTransport of a Liquid Water-Methanol Mixture in a Single Wall Carbon Nanotube
In this work, a molecular dynamics simulation of the transport of water - methanol mixture through the single wall carbon nanotube (SWCNT) is reported. Methanol and water are selected as fluid molecules since water represents a strongly polar molecule while methanol is as an intermediate between polar and strongly polar molecules. Some physical properties of the methanol-water mixture such as r...
متن کاملInvestigation of isomorph-invariance in liquid methane by molecular dynamics simulation
In this paper, isomorph invariance of liquid methane is investigated by means of constant-NVT molecular dynamics simulations. According to the data extracted from simulations, equilibrium fluctuations show strong correlation between potential energy U and virial W. We also generated isomorph state points and investigated invariance of certain thermodynamic, structural, and dynamical properties....
متن کاملSeparation of Formic Acid from Aqueous Solutions by Liquid Extraction Technique at Different Temperatures
In this study, the separation of formic acid from aqueous solutions was investigated. Liquid-liquid equilibrium (LLE) data including tie-lines was reported for water + formic acid + 2-methylpropyl ethanoate ternary mixture at (293.15 to 323.15) K and atmospheric pressure. The system shows type-I phase behavior based on Treybal’s classification because only one partially miscible binary mixture ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of chemical physics
دوره 120 16 شماره
صفحات -
تاریخ انتشار 2004