The structural and diffusive properties of an ethanol–water mixture under hydrophilic nanoscale confinement are investigated by means of molecular dynamics simulations based on the CHARMM force field. The resulting density profiles illustrate that demixing of solvents occurs at the pore wall region, which is composed of silanol molecules in our case. Ethanol molecules are more likely to attach to the wall via hydrogen bonds than water molecules. A noticeable O–H bond orientation is observed for the ethanol molecules in this region, which can be explained by the formation of two specific hydrogen bonds between ethanol and silanol. Water, in contrast, resides mostly outside the interfacial region and is in favor of forming small hydrogen bonded strings and clusters with other water molecules. This phenomenon is corroborated by both the orientation of ethanol hydroxyl groups and the radial distribution functions of the solvent oxygen atom to the silanol hydrogen atom. Ethanol selectively attaches to the wall...

Local microphase separation of a binary liquid under nanoscale confinement.

Combined Effects of Magnetic Field and Thermal Radiation on Fluid Flow and Heat Transfer of Mixed Convection in a Vertical Cylindrical Annulus

The present problem concerns with the effects of the magnetic field, mass flux diffusion and heat transfer on demixing of a binary mixture of incompressible viscous electrically conducting fluids in steady, laminar boundary layer flow in presence of a point sink at the vertex of a cone. The momentum, energy and concentration equations are reduced to non-linear coupled ordinary differential equations by similarity transformations and are solved numerically by using MATLAB’s built in solver bvp4c. The local skin friction, the Nusselt number and the Sherwood number are tabulated for various values of the parameters. These numerical results have been demonstrated graphically from which it is observed that the effects of various parameters are to separate the components of the binary mixture by collecting the rarer and lighter component near the surface of the cone and throwing the heavier one away from it.

https://jafmonline.net/JournalArchive/download?file_ID=37906&issue_ID=223

Demixing of a Binary Fluid Mixture in Case of MHD Flow with Heat and Mass Transfer due to a Point Sink

The effect of a small uniform applied horizontal magnetic field on separation of a binary mixture for the case of the fully developed natural convection of a fluid between two heated vertical walls in presence of heat generation has been studied analytically. Neglecting the induced electric field the equations governing the motion, temperature and concentration are solved by series expansion in terms of dimensionless parameter measuring buoyancy force. The solution obtained for concentration distribution is plotted against the width of the channel. It is found that the dimensionless number measuring the buoyancy force, the Hartmann number measuring the magnetic force, the thermal diffusion number and the heat generation parameter affects the species separation of rarer and lighter component significantly.

/pdf/soret-effect-due-to-natural-convection-between-heated-25s2itfg42.pdf

Soret Effect due to Natural Convection between Heated Vertical Plates with Heat Generation in a Horizontal Small Magnetic Field

Effects of a transverse magnetic field on separation of a binary mixture of
 incompressible viscous thermally and electrically conducting fluids confined
 between two stationary parallel plates are examined Both the plates are
 maintained at constant temperatures It is assumed that one of the
 components, which is rarer and lighter, is present in the mixture in a very
 small quantity The equations governing the motion, temperature and
 concentration in Cartesian coordinate are solved analytically The solution
 obtained for concentration distribution is plotted against the width of the
 channel for various values of non-dimensional parameters It is found that
 the effect of transverse magnetic field is to separate the species of rarer
 and lighter component by contributing its effect directly to the temperature
 gradient and the pressure gradient The effects of increase in the values of
 Hartmann number, magnetic Reynolds number, barodiffusion number, thermal
 diffusion number, electric field parameter and the product of Prandtl number
 and Eckert number are to collect the rarer and lighter component near the
 upper plate and throw away the heavier component towards the lower plate
 The problem discussed here derives its application in the basic fluid
 dynamics separation processes to separate the rare component of the
 different isotopes of heavier molecules where electromagnetic method of
 separation does not work

/pdf/separation-of-species-of-a-binary-fluid-mixture-confined-in-wi9r1mbtc5.pdf

Separation of species of a binary fluid mixture confined in a channel in presence of a strong transverse magnetic field

The effect of a radial magnetic field on separation of a binary mixture of incompressible viscous thermally and electrically conducting fluids confined between two concentric rotating circular cylinders with different angular velocity is examined. The equations governing the motion, temperature and concentration in cylindrical polar coordinate are solved analytically. The solution obtained in closed form for concentration distribution is plotted against the radial distances from the surface of the inner circular cylinder for various values of non-dimensional parameters. It is found that the non-dimensional parameters viz. the Hartmann number, thermal diffusion number, baro diffusion number, rotational Reynolds number, the product of Prandtl number and Eckert number, magnetic Prandtl number and the ratio of the angular velocities of inner and outer cylinders affects the species separation of rarer and lighter component significantly. The problem discussed here derives its application in the basic fluid dynamics separation processes to separate the rarer component of the different isotopes of heavier molecules where electromagnetic method of separation does not work.

Separation of species of a binary fluid mixture confined between two concentric rotating circular cylinders in presence of a strong radial magnetic field

B. R. Sharma

Papers

Separation of species of a binary fluid mixture confined between two concentric rotating circular cylinders in presence of a strong radial magnetic field