Thompson-Gibbs effect

Here c, is the concentration at the curved interface, Cpi is the concentration at the planar interface, M is the molecular weight, E is the interfacial energy, and p is the density. Thus the concentration in equilibrimn for a curved smface differs from that for a flat surface. This result is not due just to the reduction of surface area. This phenomenon is known as the Gibbs-Thompson effect. 

For thermoporometry a pure (noncontaminated) pore liquid that completely wets the inner surface of the sample under investigation is assumed. At equilibrium the chemical potentials of the still liquid and the solidified state within the pores are equal at given temperature. This equivalence provides a relationship between the pore size and the freezing point depression (Gibbs-Thompson effect) that can be used to calculate a pore size from the freezing point temperature shift ... 

Fig. 5.17 Schematic view of the interface shape close to the crucibie waii. For a strong curvature of the melting isotherm, the Gibbs-Thompson effect may be of importance. Therefore, the phase boundary is not identicai to the melting isotherm and an undercooied region ciose to the crucible wall may develop.

This equation is also called Gibbs-Thompson equation and the effect (surface curvature, vapor pressure and chemical potential) is also called the Gibbs-Kelvin effect or Kelvin effect. 

Capillarity effects arise in physical situations where significant geometrical curvatures are present. Because of the existence of surface energy, the local chemical potential becomes a function of the local radius of curvature K according to the Gibbs-Thompson equation [93Bonl] ... 

Equation (2.24a) is referred to as the Gibbs-Thompson equation or Thompson-Freundlich equation. This equation is correct only when the effect of the interface is exerted solely on the a phase, i.e. the interface belongs only to the a phase. Therefore, when using Eq. (2.24a), Eq. (2.24b) must be simultaneously satisfied. When we express Eq. (2.24a) in terms of atom activity a. 

Figure 11-58. Theoretical comparison of Joule-Thompson cooling effect with nitrogen vs. the use of a mechanical expander. (Used by permission Gibbs, C. W., (Ed.). Compressed Air and Gas Data, 1969. Ingersoll-Rand Co.)...

Theberge SM, Luther GW, Rozan TF, Rickard DT (2000) Evidence for aqueous clusters as intermediates during copper sulfide formation. Abstr Am Chem Soc 220 353 Thompson DN, Sayer RL, Noah KS (2000) Sawdust-supported passive bioremediation of western United States acid rock drainage in engineered wetland systems. Minerals Metall Process 17 96-104 Tolman RC (1966) Consideration of Gibbs theory of surface tension. J Chem Phys 16 758-774 Tolman RC (1949) The effect of droplet size on surface tension. J Chem Phys 17 333-337 Tomino H, Kusaka I, Nishioka K, Takai T (1991) Interfacial tension for small nuclei in binary nucleatioa J Crystal Growth 113 633-636... 

Fig. 8 Theoretical calculation of the effect of lamellar thickness on the melting point of a polymer crystallite using the Thompson-Gibbs equation. (From Ref 1) (View this art in color at www.dekker.com.)...

The Ostwald-Freundlich equation, applied to solubility (known as the Thompson-Gibbs effect), is as follows ... 

In studying the solubility of finely ground quartz, Stober and Arnold (122) concluded that the silica which dissolves very rapidly at first when immersed in water is much more than an adsorbed layer of SiCOH), but instead is a minute fraction of the powder which is finer than 0.1 micron and is thus, owing to the Thompson-Gibbs effect, much more soluble. 

It was shown in the same report that the effect of the finite size of ordinary crystals on their melting points (TJiL) dilute solutions) could be described by the Thompson-Gibbs equation ... 

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