Energy of film

A.J. de Vries Foam Stabflity. IV. Kinetics and Activation Energy of Film Rupture. Rec. Trav. Chim. Pays-Bas Belgique 77, 383 (1958). 

Unfortunately, the data about activation energies of NaDS and Triton-X-100 cannot be compared with the energies of film rupture determined from the Tp(Ap) dependences because equilibrium critical pressure is not reached in these foams due to various kinetic factors. On the other hand, such a comparison proves also to be impossible for Triton-X-100 foams, since the single films with radius up to r = 100 pm do not rupture even under pressure of 105 Pa at all temperatures studied. 

Toca-Herrera JL, Muller HJ, Pfohl T, Mohwald H. Influence of ethanol on the thickness and free energy of film formation of DMPC foam films. Colloids Surfaces A 1999 152 357-365. 

For two plane-parallel surfaces separated by an equilibrium distance h0, there is a minimum in specific free energy of interaction (free energy of film), U(h0) = ASFf (h0). This minimum (Fig. VII-6) is referred to as the near potential energy minimum, or simply the primary minimum. The... 

Fig. VII-6. The surface free energy of film, A, 5, as a function of film thickness, h0...

Determination of Surface Free Energy of Films Made from Hybrid Dispersions... 

The surface free energy of films made from hybrid dispersions was determined in order to look at the values of its non-polar and polar component which could provide some information on whether polyurethane-urea or acrylic/styrene polymer is on the film surface (see Table 6.30). 

While the true criterion of film stability is that the free energy of film formation should be greater than the free energy of crystallite formation, another approximate criterion is also useful. It is usually noted that if the heat of condensation of... 

Free Energy of Film for Hydrophobic Particles in Various Media (in Air = 22 mj/m )... 

Exposures were detected at energies of 25 and 45 MeV for the home roentgen film types PT-1, PT-5 and import types D4, D7, Agfa-Gevaert , MX-5 Kodak . The lead strengthening screens were used for roentgen survey. Cassettes were loaded according to 2H3 scheme. In the experiments focal distances (F) came to 1.5, 2.0, and 3.0 m. 

KBC-25 M betatron allows to x-ray steel layer with thickness 280-340mtn in an hour at radiation energy of 25 MeV and F=2 m with the help of PT-5, D4, MX-5 and D7 film types. 

A general prerequisite for the existence of a stable interface between two phases is that the free energy of formation of the interface be positive were it negative or zero, fluctuations would lead to complete dispersion of one phase in another. As implied, thermodynamics constitutes an important discipline within the general subject. It is one in which surface area joins the usual extensive quantities of mass and volume and in which surface tension and surface composition join the usual intensive quantities of pressure, temperature, and bulk composition. The thermodynamic functions of free energy, enthalpy and entropy can be defined for an interface as well as for a bulk portion of matter. Chapters II and ni are based on a rich history of thermodynamic studies of the liquid interface. The phase behavior of liquid films enters in Chapter IV, and the electrical potential and charge are added as thermodynamic variables in Chapter V. 

Fig. IV-22. Excess free energy of mixing of condensed films of octadecanol-docosyl sulfate at 25°C, at various film pressures. Top curve t = 5 dyn/cm bottom curve ir = 50 dyn/cm intermediate curves at 5-dyn/cm intervals. The curves are uncorrected for the mixing term at low film pressure. (From Ref. 246.)...

It was shown in Section X-3B that a formal calculation can be made of the film pressure, or reduction in the surface free energy of the solid, by evaluating... 

A real foam has further degrees of freedom available for estabHshing local mechanical equiHbrium the films and Plateau borders may curve. In fact, curvature can be readily seen in the borders of Figure 1. In order to maintain such curvature, there must be a pressure difference between adjacent bubbles given by Laplace s law according to the surface free energy of the film and the principle radii of curvature of the film AP = ) Note that the... 

In the case of Co—Cr having perpendicular anisotropy there is, in principle, a competition between the uniaxial anisotropy of a hexagonal stmcture and the demagnetizing energy of the thin film. In the case of magnetically separated Co—Cr columns (particulate morphology) then also the shape anisotropy contributes to the perpendicular anisotropy. 

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