Dynamic interfadal tension

S. van der Graaf, C.G.P.H. Schroen, R.G.M. van der Sman, R.M. Boom, Influence of dynamic interfadal tension on droplet formation during membrane... 

Schroder V, Behrend O, Schubert H. 1998. Effect of dynamic interfadal tension on the emulsification process using microporous, ceramic membrane. J Colloid Interface Sci 202 334-340. 

Dynamic Interfacial or Surface Tension The surface or interfadal tensions that may change dramatically as a function of the age of the surface or interface. These preequilibrium tensions are distinguished from equilibrium (limiting) tensions. See also Equilibrium Interfadal or Surface Tension. 

ChaptCT VI on transport effects on interfadal stability. New material on solubilization rates and formation of intermediate phases during diffusion in surfactant systems sections on spontaneous emulsification and dynamic surface tension revised and expanded. 

Emulsion elasticity expressed by Eq. (2.18) as the first normal stress difference, Ni, originates from the deformability of the interphase thus it is present even in Newtonian liquid blends [113]. The relation predicts that Ni increases with vdthout bound. Since drops do not deform at high viscosity ratio, A > 4, as well as when the interfadal tension coefficient is high, the elasticity should decrease as the dispersed liquid viscosity or the interfacial tension coefficient became large. Similarly, G in Eq. (2.23) and its homologues depends on the R/V12 ratio [126], but here the prediction for both limiting values of V12 is the same. As in the case of viscosity, these two direct measures of elasticity are expected to differ due to different strains imposed in the steady-state and dynamic flow fields. 

In this section, we first introduce interfadal tension and consider a resting fluid interface, and discuss its interaction with a microchannel wall. We continue with consideration of dynamically moving fluid interfaces that are relevant to multiphase microflows. The diEFerent body forces, gravitational, viscous and inertial effects are... 

Rosen, Milton J. Surfactants and Interfadal Phenomena. 3d ed. Hoboken, N.J. Wiley-Interscience, 2004. Easy-to-understand text on properties and applications of surfactants covers many topics, including dynamic surfece tension and other interfecial processes. 

Among different forces interacting at the droplet in this state, Fy, is dominant, holding the droplet at the pore opening and can be calculated with Equation (13.3) [8]. Fy is determined by the time-dependent interfadal tension, y(t), and the droplet diameter. Since the interfadal tension is influenced by the emulsifier dynamics, droplet detachment can be influenced by the emulsifier used (8) ... 

In flowing systems, the complex interplay between interfacial, gravitational, viscous and inertial forces is responsible for a variety of phase distributions and flow patterns. The dominant interfadal forces combined with the laminar nature of the flow result in very regularly shaped gas-liquid and liquid-liquid interfaces characteristic of multiphase microflows. Courbin et al. described dynamic wetting morphologies of a flat surface that is microstructured with a forest of posts upon droplet impact [44], Eijkel and co-workers [42, 48] provided a more general review of surface tension effects in the context of nanofluidic systems. The importance of interfadal forces with respect to gravity is described by the dimensionless Bond number. 

In the case of desorption the processes have the opposite direction.) Such interfadal expansions are typical for foam generation and emnlsification. The rate of adsorption relaxation determines whether the formed bnbbles/drops will coalesce npon collision, and in final reckoning— how large will be the foam volnme and the emulsion drop size [62,63]. In the following section, we focus our attention on the relaxation time of surface tension, to, which characterizes the interfadal dynamics. 

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