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It is tied to the force needed to stretch a surface. It is sometimes called (mostly for solids) surface energy and defined as the work that is required to build a unit area of a particular surface. The units of surface tension are free energy per unit area, [J/m2] or force per unit length, [N/m].
Gibbs considered the conditions in an isothermal and isobaric system of more than one component, such as a solution, where specific components might change the number of moles. To this aim, three main parameters should be defined: the Gibbs surface free energy G
10 wrz 2020 · However, from the point of view of thermodynamics, it is easier to think of surface energy. How much work is needed to increase the surface area? And how is this related to what we have described as “surface tension”?
Thermodynamics of Surfaces; Equilibrium Crystal Shape. Course will primarily focus on: atomic structure and electronic properties, chemical composition and adsorption properties of surfaces.
The surface energy across an interface or the surface tension at the interface is a measure of the energy required to form a unit area of new surface at the interface. The intermolecular bonds or cohesive forces between the molecules of a liquid cause surface tension.
Thermodynamically, the physical origin of the surface free energy is the excess Gibbs free energy of the matter at the interface. Atoms or molecules exposed at an interface are surrounded by fewer neighbors, such as solid, liquid, and gas phases, resulting in an anisotropic distribution of these neighbors, which is the characteristic of a surface.
The surface (free) energy ɛ is the energy necessary to produce unit area of new surface from bulk material by increasing the number of surface atoms. This may, e.g., happen by deforming a spherical cluster (with minimum surface area) to some flat, spheroidal shape or wire (with larger surface area).
