Disjoining Pressure and Surface Tension of a Small Drop

Langmuir ◽  
2000 ◽  
Vol 16 (7) ◽  
pp. 3502-3505 ◽  
Author(s):  
R. Tsekov ◽  
K. W. Stöckelhuber ◽  
B. V. Toshev
Keyword(s):  
Surface Tension ◽  
Disjoining Pressure ◽  
Small Drop

On the capillary forces in an idealized soil

1950 ◽  
Vol 40 (1-2) ◽  
pp. 134-142 ◽  
Author(s):  
E. C. Allberry
Keyword(s):  
Surface Tension ◽  
Experimental Method ◽  
Experimental Verification ◽  
Drop Size ◽  
Capillary Forces ◽  
Experimental Measurements ◽  
Small Drop ◽  
Soil Cohesion ◽  
Work Of Separation ◽  
Surface Tension Forces

1. The attraction between spheres, due to surface tension forces, in a lenticular drop between them is calculated for spheres in contact and at increasing separations up to the point of rupture of the drop. Hence the work of separation of the spheres is calculated.2. Experimental measurements confirm the validity of these calculations, down to very small drop sizes, where it is likely that the failure is in the experimental method. As predicted by Fisher, the force decreases with increasing drop size, while the work of separation increases. Since, however, it is shown that the smaller lenticels are more easily ruptured, no discrimination is provided between the differing explanations of Haines and Fisher of measurements made with the Atterberg apparatus for measurement of soil cohesion.An experimental verification of the validity of Fisher's calculation of the pressure deficiency inside the drop is also given.3. It is pointed out that these results depend on the geometry of the system; types of contact other than that of spheres will show different behaviour. Hence generalizations about the behaviour of a real soil, based on an idealized soil of packed spheres, may lead to erroneous conclusions.

scholarly journals Thermodynamics of interfaces extended to nanoscales by introducing integral and differential surface tensions

2021 ◽  
Vol 118 (3) ◽  
pp. e2019873118
Author(s):  
W. Dong
Keyword(s):  
Surface Tension ◽  
Surface Region ◽  
Disjoining Pressure ◽  
Scientific Concept ◽  
Inhomogeneous System ◽  
Surface Tensions ◽  
Nanoscale Systems ◽  
Thermodynamic Potentials ◽  
New Concepts ◽  
Grand Potential

As a system shrinks down in size, more and more molecules are found in its surface region, so surface contribution becomes a large or even a dominant part of its thermodynamic potentials. Surface tension is a venerable scientific concept; Gibbs defined it as the excess of grand potential of an inhomogeneous system with respect to its bulk value per interface area [J. W. Gibbs, “The Collected Works” in Thermodynamics (1928), Vol. 1]. The mechanical definition expresses it in terms of pressure tensor. So far, it has been believed the two definitions always give the same result. We show that the equivalence can break down for fluids confined in narrow pores. New concepts of integral and differential surface tensions, along with integral and differential adsorptions, need to be introduced for extending Gibbs thermodynamics of interfaces. We derived two generalized Gibbs adsorption equations. These concepts are indispensable for an adequate description of nanoscale systems. We also find a relation between integral surface tension and Derjaguin’s disjoining pressure. This lays down the basis for measuring integral and differential surface tensions from disjoining pressure by using an atomic force microscope.

Surface force at the nano-scale: observation of non-monotonic surface tension and disjoining pressure

2015 ◽  
Vol 17 (32) ◽  
pp. 20502-20507 ◽  
Author(s):  
Tiefeng Peng ◽  
Mahshid Firouzi ◽  
Qibin Li ◽  
Kang Peng
Keyword(s):  
Surface Tension ◽  
Surface Force ◽  
Md Simulations ◽  
Disjoining Pressure ◽  
Nano Scale ◽  
Disjoining Pressures

The disjoining pressures of thin aqueous salt films at different salt concentrations and temperatures were calculated using MD simulations.

Disjoining Pressure, Healing Distance, and Film Height Dependent Surface Tension of Thin Wetting Films

2014 ◽  
Vol 118 (38) ◽  
pp. 22079-22089 ◽  
Author(s):  
Jorge Benet ◽  
Jose G. Palanco ◽  
Eduardo Sanz ◽  
Luis G. MacDowell
Keyword(s):  
Surface Tension ◽  
Disjoining Pressure ◽  
Wetting Films

The Bursting of Pointed Drops in Slow Viscous Flow

1973 ◽  
Vol 40 (1) ◽  
pp. 18-24 ◽  
Author(s):  
J. Buckmaster
Keyword(s):  
Surface Tension ◽  
Viscous Fluid ◽  
Viscous Flow ◽  
Small Drop ◽  
Shape Preserving ◽  
Slender Body Theory ◽  
Slow Viscous Flow ◽  
Viscous Drops ◽  
Steady Solutions ◽  
Body Theory

Viscous drops, confined by the slow axisymmetric straining motion of a viscous fluid, are considered when the surface tension is weak. The shape of the drops is determined using slender-body theory, and it is found that steady solutions only exist for sufficiently small drop viscosities. Nonuniqueness exists, with bifurcation from a simple quadratic solution. At high drop viscosities, when there are no steady solutions, a description of the unsteady elongation of shape-preserving drops is obtained. This is the bursting phenomenon described experimentally by Taylor [1].

Modelling of disjoining pressure for Lennard-Jones free thin films

2016 ◽  
Vol 30 (10) ◽  
pp. 1650169 ◽  
Author(s):  
Tiefeng Peng ◽  
Xuechao Gao ◽  
Qibin Li ◽  
Siyuan Yang ◽  
Qizhong Tang
Keyword(s):  
Thin Films ◽  
Surface Tension ◽  
High Temperatures ◽  
Molecular Modelling ◽  
Liquid Films ◽  
Processing Technique ◽  
Disjoining Pressure ◽  
Post Processing ◽  
Lennard Jones

Development of disjoining pressure was performed to study the symmetric, Lennard-Jones (LJ) free thin films using molecular modelling. A methodology rooted from film thermodynamics was established to derive the disjoining pressure isotherm [Formula: see text], which is based on the surface tension at varied film thicknesses and can be viewed as a post-processing technique. The results showed that the disjoining pressure of LJ fluid is purely attractive. Compared with the complicated method reported previously, this methodology is demonstrated to be more convenient and readily applicable for other liquid films (e.g. water, aqueous thin films containing electrolyte or surfactants), meanwhile it can be applied at both low and high temperatures.

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