Surface Energy

Surface energy quantifies the disruption of intermolecular bonds that occur when a surface is created. In the physics of solids, surfaces must be intrinsically less energetically favorable than the bulk of a material (the molecules on the surface have more energy compared with the molecules in the bulk of the material), otherwise there would be a driving force for surfaces to be created, removing the bulk of the material (see sublimation). The surface energy may therefore be defined as the excess energy at the surface of a material compared to the bulk.

For a liquid, the surface tension (force per unit length) and the surface energy density are identical. Water has a surface energy density of 0.072 J/m2 and a surface tension of 0.072 N/m.

Cutting a solid body into pieces disrupts its bonds, and therefore consumes energy. If the cutting is done reversibly (see reversible), then conservation of energy means that the energy consumed by the cutting process will be equal to the energy inherent in the two new surfaces created. The unit surface energy of a material would therefore be half of its energy of cohesion, all other things being equal; in practice, this is true only for a surface freshly prepared in vacuum. Surfaces often change their form away from the simple "cleaved bond" model just implied above. They are found to be highly dynamic regions, which readily rearrange or react, so that energy is often reduced by such processes as passivation or adsorption.

Read more about Surface EnergyMeasuring The Surface Energy of A Liquid, Measuring The Surface Energy of A Solid, Calculating The Surface Energy of A Deformed Solid, Calculating The Surface Formation Energy of A Crystalline Solid

Other articles related to "surface energy, energy, surface, surfaces":

Surface Energy - Calculating The Surface Formation Energy of A Crystalline Solid
... In the ab initio calculations, formation energy of the crystalline solid, such as titanium (IV) oxide or magnesium oxide, can be obtained from the following equation where ... A is the area of the primitive surface unit cell and the is the energy per atomic layer in three-dimensional system ...
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... Smoluchowski developed the equation under five assumptions Particles are spherical, nonconducting, and monodispersed ... Laminar flow around the particles occurs (Reynolds number >1) ...
Sessile Drop Technique - Determining Surface Energy - Three Component Theories - The Van Oss Theory
... The van Oss theory separates the surface energy of solids and liquids into three components ... It includes the dispersive surface energy, as before, and subdivides the polar component as being the sum of two more specific components the surface energy due to acidic ... The acid component theoretically describes a surface’s propensity to have polar interactions with a second surface that has the ability to act basic by ...
Contact Mechanics - Adhesive Contact Between Elastic Bodies - Johnson-Kendall-Roberts (JKR) Model of Elastic Contact
... contact using a balance between the stored elastic energy and the loss in surface energy ... two spheres where is the radius of the area of contact, is the applied force, is the total surface energy of both surfaces per unit contact area, are the radii, Young's moduli, and Poisson's ... of adhesion as where are the adhesive energies of the two surfaces and is an interaction term, we can write the JKR contact radius as The tensile load at separation is and the critical contact ...
Sessile Drop Technique - Determining Surface Energy
... While surface energy is conventionally defined as the work required to build a unit of area of a given surface, when it comes to its measurement by the sessile drop technique, the surface energy is ... components simplify the system by lumping surface energy into one number, while more rigorous methods with more components are derived to distinguish between various components of the surface ... Again, the total surface energy of solids and liquids depends on different types of molecular interactions, such as dispersive (van der Waals), polar, and acid/base interactions, and is ...

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