Relative interfacial energy

The relative interfacial energies between different phases influence how they interact with each other. As an example, consider the wetting behavior of a liquid water droplet on the surface of a solid, as illustrated in Figure 6.11. The contact angle between the water droplet and the solid surface (6) is determined by the balance between three different interfacial energy terms ... 

However, the spreading of a surfactant monolayer from a volatile solvent leaves behind a film that may not be in thermodynamic equilibrium with its bulk crystalline form or the aqueous subphase. It has been proposed that this is a result of the relatively high energy barriers to film collapse or dissolution into the subphase as compared with lowered interfacial free energy when a stable, insoluble surfactant monolayer is formed (Gershfeld, 1976). The rate at which a whole system approaches true equilibrium in such a system is often so slow that the monolayer film can be treated for most purposes as though it were at equilibrium with the subphase. 

The distribution of the liquid is determined by the interfacial energy between the liquid and the solid matrix relatively to the grain boundary energy. An example is shown in Figure 6.11 (a), where an important characteristic of grain boundaries, the... 

Complementary to using repulsive interactions in order to achieve shape control, attractive interactions of relatively large building blocks, which are rationally designed regarding their shape, polarity, and functional groups, can be employed for intramolecular self-assembly [23]. In this case, the molecular structure optimizes itself to realize specific interactions between the blocks and minimize the interfacial energy. 

Since it is relatively easy to transfer molecules from bulk liquid to the surface (e.g. shake or break up a droplet of water), the work done in this process can be measured and hence we can obtain the value of the surface energy of the liquid. This is, however, obviously not the case for solids (see later section). The diverse methods for measuring surface and interfacial energies of liquids generally depend on measuring either the pressure difference across a curved interface or the equilibrium (reversible) force required to extend the area of a surface, as above. The former method uses a fundamental equation for the pressure generated across any curved interface, namely the Laplace equation, which is derived in the following section. 

Fig. 6.116. Gibbs energy change for adsorption of amyl alcohol (1) and acetonitrile (2) on a number of sp-metals and Ag, as a function of the relative interfacial parameter. (Reprinted from S. Trasatti, Russ. J. Electrochem. 31 713, 1995, Fig. 8.)...

Figure 23.3 Relative increase of strain energy (AgcV) and interfacial energy (-(A) of...

The Cu-Co system is a particularly simple precipitation system in which a Corich /3 phase precipitates in a Cu-rich terminal a phase. The f.c.c. lattices of both phases are well matched in three dimensions, so that the precipitate interfaces are coherent with respect to either lattice as a reference structure and the interfacial energy is sufficiently isotropic so that they are almost spherical, as in Fig. 19.2. Both the interfacial energy and strain energy are therefore relatively low and the nucleation of the f3 phase is therefore relatively easy and occurs homogeneously. This system has been used to test the applicability of the classical nucleation theory (Section 19.1.1) [11, 12]. In this work, the experimental conditions under which... 

Segregation of the incompatible molecular segments takes place with formation of distinct nano-compartments organized on a one-dimensional (ID), two-dimensional (2D), or three-dimensional (3D) periodic lattice, separated by interfaces. These interfaces tend to be minimal in order to reduce the interfacial energy stored in the system. For amphiphilic molecules without anisometric segments (flexible amphiphiles) the mesophase type is mainly determined by the relative volume of the two incompatible segments, as shown in Fig. 2. 

Interfacial Energy of Adhesion. When the polyelectrolyte-grafted nylon surface, in equilibrium with 50% relative humidity, is brought into contact with water or a salt solution, various interactions will occur together they comprise the reversible work of adhesion or free energy of adhesion at the interface of these two phases. This free energy of adhesion should be composed of the following contributions ... 

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