E+00 0 Gramos dados 0 Cambiar Resultado Unidades Datos Ecuación Datos Ecuación Notas hermosas de Valen Gibbs -Donnan Equilibrium Material. Regulator of extracellular fluid, Donnan effect. The Gibbs-Donnan equilibrium across the epithelium established the Ecuación de Starling. Roberto Francisco Herrero Rodríguez PDI Teaching and Researching File at University of a Coruña.

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The Gibbs—Thomson effect, in common physics usage, refers to variations in vapor pressure or chemical potential across a curved surface or interface.

Potencial de membrana en reposo, equilibrio de Gibbs Donnan y ecuación de Nernst – YouTube

The existence of a positive interfacial energy will increase the energy required to form small particles with high curvature, and these particles will exhibit an increased vapor pressure. More specifically, the Gibbs—Thomson effect refers to the observation that small crystals are in equilibrium with their liquid melt at a lower temperature than large crystals.

The technique is closely related to using gas adsorption to measure pore sizes, but uses the Gibbs—Thomson equation ecuacuon than the Kelvin equation.

As such it has given rise to various related techniques for measuring pore size distributions. See Thermoporometry and Cryoporometry. The Gibbs—Thomson effect lowers both melting and freezing point, and also raises boiling point.

However, simple cooling of an all-liquid sample usually leads to a state of non-equilibrium super cooling and only eventual non-equilibrium freezing. To obtain a measurement of the equilibrium freezing event, it is necessary to first cool enough to freeze a sample with excess liquid outside the pores, then warm the sample until the liquid in the pores is all melted, but the bulk material is still frozen.

Then, on re-cooling the equilibrium gbibs event can be measured, as the external ice will then grow into the pores. The melting event can be expected to provide more accurate information on the pore body.


Very similar equations may be applied to the growth and melting of crystals in the confined geometry of porous systems.

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The Gibbs—Thomson equation may be written in a compact form: As early asRobert von Helmholtz son of the German physicist Hermann von Helmholtz had observed that finely dispersed liquids have a higher vapor pressure. Thomson derived the Gibbs—Thomson equation inhe did not.

That name was in use by or earlier; [21] it originally referred to equations concerning the adsorption of solutes by interfaces between two phases — equations that Gibbs and then J. Thomson, not William Thomson Lord Kelvin. InWilliam Thomson published an equation describing capillary action and relating the curvature of a liquid-vapor interface to the vapor pressure: In his dissertation ofRobert von Helmholtz son of German physicist Hermann von Helmholtz showed how the Ostwald-Freundlich equation.

The Gibbs—Thomson equation can also be derived directly from Gibbs’ equation for the energy of an interface between phases. It should be mentioned that in the literature, there is still not agreement about the specific equation to which the name “Gibbs—Thomson equation” refers.

For example, in the case of some authors, it’s another name for the “Ostwald-Freundlich equation” [29] —which, in turn, is often called the “Kelvin equation”—whereas in the case of other authors, the “Gibbs—Thomson relation” is the Gibbs free energy that’s required to expand the interface, [30] and so forth.

From Wikipedia, the free encyclopedia.


Jan”Curvature-dependent metastability of the solid phase and the freezing-melting hysteresis in pores”, Phys. ImagingElsevier Netherlands25 gibbbs Dec”The melting behavior of organic materials confined in porous solids”, J.

The evidence from neutron diffraction and NMR relaxation. Carl Winter,v. The relevant passage is reprinted on page of volume 1 of the ecucaion Melting of the finest powder. Available on-line in English translation at: National Research Council Canada. Donan influence of particle size on the melting point.

University of Minnesota,pages 26— However, on pages —Thomson considered the effects of temperature and surface tension on the solubility of salts in spherical droplets, and he obtained an equation for that phenomenon which has a form similar to that of the Gibbs—Thomson equation. Ernst Rie first published the Gibbs—Thomson equation in in his dissertation for a degree from the University of Vienna.


Extracts from that dissertation were published in in: Influence of surface tension on melting and freezingAnzeiger der Akademie der Wissenschaften in Wien: State Museum of Austria. The Gibbs—Thomson equation appears on page Macallum October 7, “Surface tension in relation to cellular processes,” Science32 After explaining the Gibbs—Thomson principle and its origin on pagehe uses the term “Gibbs—Thomson principle” on page Macallum October 14, “Surface tension euacion relation to cellular processes.

II,” Science32 I”, Journal of Physical Chemistry28 7: Willard Gibbsvol. Yale University Press,page InGibbs published an equation concerning the adsorption of a solute by an interface between two donnna, and inJ.

Gibbs–Thomson equation

Thomson published an equation concerning the same phenomenon, which he’d derived via a different method but which superficially resembled Gibbs’ result. Apparently both equations were eventually known as “the Gibbs—Thomson equation”. See equation 2 on page On pages —, Robert von Helmholtz converts Kelvin’s equation to the Ostwald-Freundlich equation.

McDonald December “Homogeneous nucleation of supercooled water drops”, Journal of Meteorology The equation for the energy that’s required to create a surface between two phases appears on page Longmans, Green and Co. Atomistic and collective processes New York: Plenum Press,page Barsoum, Fundamentals of Ceramics New York: Retrieved from ” https: Views Read Edit View history. This page was last edited on 6 Octoberat By using this site, you agree to the Terms of Use and Privacy Policy.