Spreading coefficient, definition

In accordance with Harkins definition the following spreading coefficients are distinguished initial s, semi-initial s and final (equilibrium) se spreading coefficients... 

Since information about the instability of asymmetric films provided from the spreading and enter coefficients is incomplete, it has been proposed [541,542] to use generalised spreading coefficients 5s on the basis of Eqs. (3.157-3.160). By definition the generalised spreading coefficient is [541]... 

When a droplet is placed on a solid surface, either it does not move and has a definite contact angle between the liquid and the solid phase, or it spreads across the surface to form a wetting film [39]. This criterion is expressed by defining a parameter termed the equilibrium spreading coefficient, Sus, where... 

The definitions of the classic entry and spreading coefficients, given by Equations 3.1 through 3.12 in Section 3.2, and for the bridging coefficient, given by Equations 4.29 through 4.31 in Section 4.5.1, can be transformed to the present context if we make the substitutions... 

Fiere, S is termed the spreading coefficient. A more convenient definition of S is in terms of measurable interfacial tensions ... 

According to the Harkins definition of the spreading coefficient, it is the difference between the original energy (surface energy of the water-air interface, WA) and the final energy, in the case of an oil-water (OW) and an oil-air (OA) interface. 

Starting from the definition of the Harkins spreading coefficient S. show that the spreading coefficient can be equivalently given as the difference between the work of adhesion of oil (o) and water (w) and the woik of cohesion of oil (o) ... 

Xji is the spreading coefficient giving the tendency of polymer j to spread on polymer i and the cfs are the interfacial tensions of the different polymer pairs. If the spreading coefficients are all negative for a definite set of three polymers, the three phases are predicted to meet along a line of contact. Otherwise, spreading (or encapsulation) is observed. 

The Dykstra-Parsons coefficient is a normalized measure of the spread of a permeability distribution that is bounded between zero and one. The formal definition is... 

Two other factors, however, combine to make a pressing need to reach a definitive experimental value for the thermal DR rate coefficient. The observation of Hj in diffuse interstellar clouds has made it possible to determine the abundance of The factor of 10 spread in the... 

In order to cause spontaneous spreading of an aqueous surfactant solution (W) over a second immiscible liquid (O) as substrate, the definite relationship between surface and interfacial tension, known as the spreading (Harkins) coefficient Swo should be fulfilled. If Swo> as defined by the equation... 

If the spreading pressure depends only on the total adsorbed phase concentration, which may be a reasonable approximation for many systems, this definition is equivalent to the Myers and Prausnitz definition [Eq. (3.49)], The condition for thermodynamic consistency with this definition of activity coefficients is ... 

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