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Films film pressure concept

With less strictness the surface pressure can be compared with the three-dimensional pressure on isolated matter and, with due consideration of the effects of the underlying water molecules on the behaviour of the molecules in the film, the conception of surface pressure as the effect of the repulsive forces between the film molecules and the boundary A of the film has yielded a very large part of our present information as to the molecular structure of these films.1... [Pg.22]

The CBF/NBF transition has already been considered in Section 3.4.1 with respect to the experimental n(/i) isotherms of disjoining pressure obtained with the Thin Liquid Film-Pressure Balance Technique. Theoretical concepts and comparison with the DLVO- and contemporary theories describing surface forces acting in this range of film thicknesses have also been discussed. [Pg.199]

The topics of the early scientific work of Derjaguin and his collaborators was the evaluation of the term "disjoining pressure" as basic property of a thin liquid film. Derjaguin Obuchov (1936) and Derjaguin Kussakov (1939) have detected the growth of repulsive forces in such films as the film becomes thitmer. The classic thermodynamics of Gibbs was extended by the thermodynamic formulation of the disjoining pressure concept. [Pg.497]

Centrifugal Flow Control, Fig. 5 Schematic of the dissolvable-film DF) valving concept (a). The DF seals an air-filled chamber which is hydrostatically pressurized by the centrifugal force exerted on the incoming liquid. [Pg.376]

Since relative to water for several halogenated aromatic n-alkane series could be determined, some additional surface chemical properties for these same series were calculated. The concepts of these properties and the appropriate equations had been developed by Pomerantz, Clinton and Zisman. Table V lists the initial film pressure (where ba..= Sba denotes the respective organic... [Pg.73]

Thus it is necessary to find alternative approach to describe the physical mechanism of two-side filling of conical capillaries with hquids. Theoretical model of film flow in conical dead-end capillary is based on the concept of disjoining pressure II in thin liquid film [13]... [Pg.616]

In the preceding derivation, the repulsion between overlapping double layers has been described by an increase in the osmotic pressure between the two planes. A closely related but more general concept of the disjoining pressure was introduced by Deijaguin [30]. This is defined as the difference between the thermodynamic equilibrium state pressure applied to surfaces separated by a film and the pressure in the bulk phase with which the film is equilibrated (see section VI-5). [Pg.181]

Equation 39 can often be simplified by adopting the concept of a mass transfer unit. As explained in the film theory discussion eadier, the purpose of selecting equation 27 as a rate equation is that is independent of concentration. This is also tme for the Gj /k aP term in equation 39. In many practical instances, this expression is fairly independent of both pressure and Gj as increases through the tower, increases also, nearly compensating for the variations in Gj. Thus this term is often effectively constant and can be removed from the integral ... [Pg.25]

These results clearly demonstrate the high potential of the single source precursor concept. In particular, the low deposition temperatures necessary for the stibinoalanes and the low carbon contents of the resulting material films are very promising results. However, the low vapor pressure of the heterocycles, which require sublimation temperatures about 130 °C, are a major drawback. [Pg.303]

The explanation of the pressure-independent region during the ultrafiltration of macromolecules requires the arbitrary introduction of the concept of a gel-layer in the film model. A more complete description of the dependence of the membrane permeation rate on the applied pressure may be given by considering the effect of the osmotic pressure of the macromolecules as described by Wijmans et alS18 Equation 8.2 may then be written as ... [Pg.450]

A modified superheat theory was proposed by Shick to explain molten salt (smelt)-water thermal explosions in the paper industry (see Section IV). (Smelt temperatures are also above the critical point of water.) In Shick s concept, at the interface, salt difiuses into water and water into the salt to form a continuous concentration gradient between the salt and water phases. In addition, it was hypothesized that the salt solution on the water side had a significantly higher superheat-limit temperature and pressure than pure water. Thicker, hotter saltwater films could then be formed before the layer underwent homogeneous nucleation to form vapor. [Pg.161]

The above concept of duplex film can be used to explain both the stability of microemulsions and the bending of the interface. Considering that initially the flat duplex film has different tensions (i.e., different values) on either side of it, then the deriving force for film curvature is the stress of the tension gradient which tends to make the pressure or tension in both sides of the curved film the same. This is schematically shown in Figure 1. For example if ir > ir on the flat... [Pg.155]

This concept is further demonstrated in Figure 8.12, which reports the performances of two Pd thin-film membranes with different morphology in H202 synthesis at room temperature and atmospheric pressure. [Pg.277]


See other pages where Films film pressure concept is mentioned: [Pg.119]    [Pg.122]    [Pg.122]    [Pg.81]    [Pg.127]    [Pg.4]    [Pg.35]    [Pg.173]    [Pg.596]    [Pg.36]    [Pg.371]    [Pg.417]    [Pg.138]    [Pg.247]    [Pg.155]    [Pg.466]    [Pg.1188]    [Pg.558]    [Pg.116]    [Pg.4]    [Pg.448]    [Pg.328]    [Pg.156]    [Pg.428]    [Pg.81]    [Pg.93]    [Pg.117]    [Pg.130]    [Pg.99]    [Pg.196]    [Pg.390]    [Pg.448]    [Pg.140]    [Pg.187]   
See also in sourсe #XX -- [ Pg.2 , Pg.122 ]

See also in sourсe #XX -- [ Pg.2 , Pg.122 ]




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