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A. K. Helmy - One of the best experts on this subject based on the ideXlab platform.

  • Basic features of the Young Equation
    Physical Chemistry: An Indian Journal, 2010
    Co-Authors: A. K. Helmy, E. A. Ferreiro
    Abstract:

    The Young Equation describes the equilibrium of three heterogeneous masses in contact and are homogeneous quite up to the separating interfaces, with respect to the density of energy, entropy and the chemical potential of the components (chemical species). The basic characteristics of the interfacial energy terms of the Equation and their interrelations especially for the solid-water-vapour system are examined in detail. The solid-vapour interfacial energy, the introduction of surface pressure in the Young Equation and their relation with monolayer coverage of adsorbate are considered in detail. The stability of the system and the conditions under which the Equation is applied are emphasized.

  • The water/graphitic-carbon interaction energy
    Applied Surface Science, 2007
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract The water/graphitic-carbon interaction energy was obtained for a sample having a water surface site adsorption density of 13.3 μmol m −2 . The interaction energy was determined from the spreading pressure of water, its surface tension and the water contact angle and using a formula obtained by the combination of the Young Equation with a general Equation of pair interaction. The values obtained for contact angles 42° and 86° are 7.63 and 7.18 kJ mol −1 of water are similar to the water binding energies obtained from molecular dynamic simulations of water droplets on a graphite surface: 6.7–8.33 kJ mol −1 .

  • The surface energy of talc.
    Journal of colloid and interface science, 2005
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract The determination of an average value for the surface energy of talc ( γ ¯ S ) via solid–water interfacial interactions is described. It is based on a formula obtained by the combination of the Young Equation with a general Equation of pair interaction. Important features of the method are (a) the use of the Young Equation to determine the range where the value of the surface energy lies and (b) the determination of the mean value within this range using a probability function. The value found is 217.31 mJ m −2 in the range 193.36 – 257.43 mJ m −2 .

  • The surface energy of kaolinite
    Colloid and Polymer Science, 2004
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    The surface energy of kaolinite was determined from the water adsorption isotherm, the water/kaolinite contact angle, and the surface tension of water, using a formula obtained by combining the Young Equation with the general Equation of pair interaction. This formula could be represented by a polynomial function whose roots gave one real value of 252.57±2.75 mJ m−2 for the surface energy of kaolinite. An important feature of the procedure for obtaining this energy is the use of the Young Equation to determine the range in which the value of the surface energy lies.

  • The surface energy of montmorillonite.
    Journal of colloid and interface science, 2003
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract By combining the relation that describes pair interaction in binary mixtures with the Young Equation, a formula is obtained for calculating the surface energy of montmorillonite as a function of the surface pressure, the surface tension of water, and the liquid/solid contact angle. The formula is an Equation of an inverted parabola, which could be represented by a polynomial function. Roots of the polynomial gave one real value of 205.066±2.764 mJ m−2 for the surface energy of montmorillonite. The value obtained is of the expected magnitude and probably is better than those obtained by previous approaches.

Anatoly I. Rusanov - One of the best experts on this subject based on the ideXlab platform.

  • New thermodynamic potentials for surface science
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014
    Co-Authors: Anatoly I. Rusanov
    Abstract:

    J-potential belongs to the group of novel thermodynamic potentials for arbitrarily loaded solids. The article considers two modified forms of J-potential especially convenient for surface science. Definitions are given and fundamental Equations are derived for bulk phases, interfaces, and interfacial lines. The application of J-potential is illustrated by deriving the Neumann and Gibbs Equations for a number of interfaces meeting at a line, and the classical Young Equation.

  • The line tension and the generalized Young Equation: the choice of dividing surface
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004
    Co-Authors: Anatoly I. Rusanov, Alexander K. Shchekin, D. V. Tatyanenko
    Abstract:

    Using Gibbs method of dividing surfaces, the condition of equilibrium of a sessile drop on a flat non-deformable solid substrate is investigated. The dependence of the line tension on the curvature radius of the dividing three-phase contact line is found. It has been derived a relationship between the partial derivative of the line tension with respect to the curvature radius of the three-phase contact line (which stands in the generalized Young Equation) and the total derivative of the line tension with respect to the same radius along the equilibrium states. Various approximated formulas of the generalized Young Equation used in the literature are analyzed.

  • Effect of roughness in the generalized Young Equation
    Colloid journal of the Russian Academy of Sciences, 1998
    Co-Authors: Anatoly I. Rusanov
    Abstract:

    The notions of line roughness as a more detailed characteristic of the solid surface and the roughness of a three phase contact line, which may be caused by both surface roughness and its microheterogeneity, were introduced. The general principle accounting for the effect of roughness in thermodynamic relationships was formulated. As an example, the generalized Young Equation accounting for the roughness of the three phase contact line and possible difference in the surface roughnesses of dry and wetted surfaces was derived. The Wenzel Equation was generalized to the case of rough surfaces.

  • EFFECT OF CONTACT LINE ROUGHNESS ON CONTACT ANGLE
    Mendeleev Communications, 1996
    Co-Authors: Anatoly I. Rusanov
    Abstract:

    The generalized Young Equation allowing for the roughness of the three-phase contact line has been derived and applied to an explanation of experimental results on the contact angle anisotropy of a sessile drop on deformed elastomers.

Silvia G. De Bussetti - One of the best experts on this subject based on the ideXlab platform.

  • The water/graphitic-carbon interaction energy
    Applied Surface Science, 2007
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract The water/graphitic-carbon interaction energy was obtained for a sample having a water surface site adsorption density of 13.3 μmol m −2 . The interaction energy was determined from the spreading pressure of water, its surface tension and the water contact angle and using a formula obtained by the combination of the Young Equation with a general Equation of pair interaction. The values obtained for contact angles 42° and 86° are 7.63 and 7.18 kJ mol −1 of water are similar to the water binding energies obtained from molecular dynamic simulations of water droplets on a graphite surface: 6.7–8.33 kJ mol −1 .

  • The surface energy of talc.
    Journal of colloid and interface science, 2005
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract The determination of an average value for the surface energy of talc ( γ ¯ S ) via solid–water interfacial interactions is described. It is based on a formula obtained by the combination of the Young Equation with a general Equation of pair interaction. Important features of the method are (a) the use of the Young Equation to determine the range where the value of the surface energy lies and (b) the determination of the mean value within this range using a probability function. The value found is 217.31 mJ m −2 in the range 193.36 – 257.43 mJ m −2 .

  • The surface energy of kaolinite
    Colloid and Polymer Science, 2004
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    The surface energy of kaolinite was determined from the water adsorption isotherm, the water/kaolinite contact angle, and the surface tension of water, using a formula obtained by combining the Young Equation with the general Equation of pair interaction. This formula could be represented by a polynomial function whose roots gave one real value of 252.57±2.75 mJ m−2 for the surface energy of kaolinite. An important feature of the procedure for obtaining this energy is the use of the Young Equation to determine the range in which the value of the surface energy lies.

  • The surface energy of montmorillonite.
    Journal of colloid and interface science, 2003
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract By combining the relation that describes pair interaction in binary mixtures with the Young Equation, a formula is obtained for calculating the surface energy of montmorillonite as a function of the surface pressure, the surface tension of water, and the liquid/solid contact angle. The formula is an Equation of an inverted parabola, which could be represented by a polynomial function. Roots of the polynomial gave one real value of 205.066±2.764 mJ m−2 for the surface energy of montmorillonite. The value obtained is of the expected magnitude and probably is better than those obtained by previous approaches.

E. A. Ferreiro - One of the best experts on this subject based on the ideXlab platform.

  • Basic features of the Young Equation
    Physical Chemistry: An Indian Journal, 2010
    Co-Authors: A. K. Helmy, E. A. Ferreiro
    Abstract:

    The Young Equation describes the equilibrium of three heterogeneous masses in contact and are homogeneous quite up to the separating interfaces, with respect to the density of energy, entropy and the chemical potential of the components (chemical species). The basic characteristics of the interfacial energy terms of the Equation and their interrelations especially for the solid-water-vapour system are examined in detail. The solid-vapour interfacial energy, the introduction of surface pressure in the Young Equation and their relation with monolayer coverage of adsorbate are considered in detail. The stability of the system and the conditions under which the Equation is applied are emphasized.

  • The water/graphitic-carbon interaction energy
    Applied Surface Science, 2007
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract The water/graphitic-carbon interaction energy was obtained for a sample having a water surface site adsorption density of 13.3 μmol m −2 . The interaction energy was determined from the spreading pressure of water, its surface tension and the water contact angle and using a formula obtained by the combination of the Young Equation with a general Equation of pair interaction. The values obtained for contact angles 42° and 86° are 7.63 and 7.18 kJ mol −1 of water are similar to the water binding energies obtained from molecular dynamic simulations of water droplets on a graphite surface: 6.7–8.33 kJ mol −1 .

  • The surface energy of talc.
    Journal of colloid and interface science, 2005
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract The determination of an average value for the surface energy of talc ( γ ¯ S ) via solid–water interfacial interactions is described. It is based on a formula obtained by the combination of the Young Equation with a general Equation of pair interaction. Important features of the method are (a) the use of the Young Equation to determine the range where the value of the surface energy lies and (b) the determination of the mean value within this range using a probability function. The value found is 217.31 mJ m −2 in the range 193.36 – 257.43 mJ m −2 .

  • The surface energy of kaolinite
    Colloid and Polymer Science, 2004
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    The surface energy of kaolinite was determined from the water adsorption isotherm, the water/kaolinite contact angle, and the surface tension of water, using a formula obtained by combining the Young Equation with the general Equation of pair interaction. This formula could be represented by a polynomial function whose roots gave one real value of 252.57±2.75 mJ m−2 for the surface energy of kaolinite. An important feature of the procedure for obtaining this energy is the use of the Young Equation to determine the range in which the value of the surface energy lies.

  • The surface energy of montmorillonite.
    Journal of colloid and interface science, 2003
    Co-Authors: A. K. Helmy, E. A. Ferreiro, Silvia G. De Bussetti
    Abstract:

    Abstract By combining the relation that describes pair interaction in binary mixtures with the Young Equation, a formula is obtained for calculating the surface energy of montmorillonite as a function of the surface pressure, the surface tension of water, and the liquid/solid contact angle. The formula is an Equation of an inverted parabola, which could be represented by a polynomial function. Roots of the polynomial gave one real value of 205.066±2.764 mJ m−2 for the surface energy of montmorillonite. The value obtained is of the expected magnitude and probably is better than those obtained by previous approaches.

A.i. Rusanov - One of the best experts on this subject based on the ideXlab platform.

  • The Influence of Hydrostatic Pressure on the Contact Angle of a Sessile Bubble
    Colloid Journal, 2019
    Co-Authors: N. E. Esipova, A.i. Rusanov, V. D. Sobolev, S. V. Itskov
    Abstract:

    Although usual pressures have typically a weak effect on the properties of condensed phases and their surface layers, a parameter has been found in the surface physical chemistry—a contact angle at a three-phase contact line—that is rather sensitive to hydrostatic pressure. Experiments with an air bubble adhered to a solid surface immersed in water have shown that an increase in the hydrostatic pressure by less than two times causes a growth of the contact angle by more than 10°, if the angle is markedly smaller than 90°. Therewith, the three-phase contact line remains immobile, and only the liquid−gas interface changes its orientation. If the angle (no matter, acute or obtuse) is close to 90°, the three-phase contact line acquires mobility as an alternative way to reach an equilibrium . A thermodynamic theory has been developed on the basis of the generalized Young Equation to explain these phenomena. It has been shown that, when the three-phase contact line is fixed, a growth of the pressure in a liquid always leads to a rise in the contact angle.

  • Thermodynamics of solid surfaces
    Surface Science Reports, 2002
    Co-Authors: A.i. Rusanov
    Abstract:

    In contrast to the thermodynamics of fluid surfaces, the thermodynamics of solid surfaces was not elaborated in detail by Gibbs and other founders of surface thermodynamics. During recent decades, significant progress in this field has been achieved in both the understanding of old notions, like chemical potentials, and in formulating new areas. Applying to solid surfaces, basic relationships of classical theory of capillarity, such as the Laplace Equation, the Young Equation, the Gibbs adsorption Equation, the Gibbs-Curie principle, the Wulff theorem and the Dupre rule, were reformulated and generalized. The thermodynamics of self-dispersion of solids and the thermodynamics of contact line phenomena were developed as well. This review provides a fresh insight into the modern state of the thermodynamics of solid surfaces. Not only a solid surface itself, both in a macroscopic body and in the system of fine particles, but also the interaction of solid surfaces with fluid phases, such as wetting phenomenon, will be analyzed. As the development of surface thermodynamics has given a powerful impetus to the creation of new experimental methods, some of these will be described as examples.