Drop size effect on contact angle explained by nonextensive thermodynamics. Young's equation revisited

2007 ◽  
Vol 314 (2) ◽  
pp. 604-614 ◽  
Author(s):  
Pierre Letellier ◽  
Alain Mayaffre ◽  
Mireille Turmine
Keyword(s):  
Contact Angle ◽  
Size Effect ◽  
Drop Size ◽  
Nonextensive Thermodynamics ◽  
Young's Equation

scholarly journals Wettability on Different Surfaces

2020 ◽  
Author(s):  
Yeeli Kelvii Kwok
Keyword(s):  
Contact Angle ◽  
Textured Surface ◽  
Original Material ◽  
Textured Surfaces ◽  
Hydrophobic Surfaces ◽  
Hydrophilic Surfaces ◽  
Young's Equation

Wettability has been explored for 100 years since it is described by Young’s equation in 1805. It is all known that hydrophilicity means contact angle (θ), θ < 90°; hydrophobicity means contact angle (θ), θ > 90°. The utilization of both hydrophilic surfaces and hydrophobic surfaces has also been achieved in both academic and practical perspectives. In order to understand the wettability of a droplet distributed on the textured surfaces, the relevant models are reviewed along with understanding the formation of contact angle and how it is affected by the roughness of the textured surface aiming to obtain the required surface without considering whether the original material is hydrophilic or hydrophobic.

THE MODIFIED YOUNG'S EQUATION FOR THE CONTACT ANGLE OF A SMALL SESSILE DROP FROM AN INTERFACE DISPLACEMENT MODEL

1999 ◽  
Vol 13 (27) ◽  
pp. 3255-3259 ◽  
Author(s):  
HARVEY DOBBS
Keyword(s):  
Contact Angle ◽  
Sessile Drop ◽  
Unit Length ◽  
Excess Free Energy ◽  
Line Tension ◽  
Rigid Substrate ◽  
Three Phase ◽  
Interface Displacement ◽  
Displacement Model ◽  
Young's Equation

We derive the modified Young's equation for the contact angle of a fluid droplet on a rigid substrate using an interface displacement model and identify the line tension with the excess free energy per unit length calculated previously for a straight three-phase contact line.

Drop Size Dependence of the Contact Angle of Nanodroplets

2005 ◽  
Vol 22 (4) ◽  
pp. 787-790 ◽  
Author(s):  
Guo Hong-Kai ◽  
Fang Hai-Ping
Keyword(s):  
Contact Angle ◽  
Drop Size ◽  
Size Dependence ◽  
Drop Size Dependence

A direct measurement of the influence of vapour, of liquid and of oriented monolayers on the interfacial energy of mica

1967 ◽  
Vol 301 (1464) ◽  
pp. 47-56 ◽  
Keyword(s):  
Contact Angle ◽  
Marked Reduction ◽  
Polar Medium ◽  
Monomolecular Layer ◽  
Interfacial Energies ◽  
A Value ◽  
Cleavage Energy ◽  
Solid Liquid ◽  
Work Done ◽  
Young's Equation

A cleavage technique has been used to measure solid/fluid interfacial energies, and to study directly the effect of various media on these energies. Solid/vapour and solid/liquid interfacial energies were measured by cleaving mica specimens first in an atmosphere of vapour and then in the corresponding liquid. In this way we have a direct means of checking the validity of Young’s equation. Results obtained with water, as representative of a polar medium, and hexane, as representative of a non-polar medium show that Young’s equation holds for systems with zero contact angle. The effect of the humidity of the surrounding atmosphere on the cleavage of mica was also investigated. Water vapour was found to produce a marked reduction in the cleavage energy. In another set of experiments the cleavage technique was used to determine the work done in separating mica surfaces covered with an adsorbed monomolecular layer of fatty acid. The results yield a value of 37 erg/cm 2 for the surface energy of a lauric acid monolayer on mica.

The effect of drop size on contact angle

1979 ◽  
Vol 71 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Robert J Good ◽  
M.N Koo
Keyword(s):  
Contact Angle ◽  
Drop Size

The contact angle for a droplet on homogeneous and spherical concave surfaces

2016 ◽  
Vol 30 (07) ◽  
pp. 1650078
Author(s):  
Ai-Jun Hu ◽  
Bao-Zhan Lv ◽  
Xiao-Song Wang ◽  
Long Zhou
Keyword(s):  
Contact Angle ◽  
Chemical Potential ◽  
Rough Surfaces ◽  
Line Tension ◽  
Equilibrium Contact Angle ◽  
Precursor Film ◽  
Phase System ◽  
Spherical Droplet ◽  
Dividing Surface ◽  
Young's Equation

Wetting of droplets on homogeneous and spherical concave rough surfaces is investigated based on thermodynamics. In this study, neglecting the droplet gravity and the thickness of the precursor film of the liquid–vapor interface, the three-phase system is divided into six parts using Gibbs concept of dividing surface. The system Helmholtz free energy is established based on thermodynamics. Supposing the temperature and chemical potential to be constant, a new generalized Young’s equation of the equilibrium contact angle for a spherical droplet on a spherical concave rough surfaces is obtained including the line tension effects. Under certain conditions, this generalized Young’s equation is the same as the Rusanov’s equation.

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