APPLICATION OF VAN-OSS-CHAUDHURY-GOOD THEORY OF WETTABILITY TO INTERPRETATION OF INTERFACIAL FREE-ENERGIES OF HETEROGENEOUS NUCLEATION

The Van Oss-Chaudhury-Good (VCG) theory of wettability is used to unde rstand the role of hydrophilic and hydrophobic interfacial forces in p romoting heterogeneous nucleation from solution-phase precipitation pr ocesses. The interfacial free energy of nucleation for heterogeneous p rocesses is simply related to the relative nucleus-solvent and nucleus -surface areas and their individual interfacial free energies. VCG the ory is used to extend this relationship to the individual surface free energies of the isolated phases. Surface free energies obtained from, for example, surface tension measurements and surface probe contact-a ngle measurements provide independent measure of the needed quantities . We use classical nucleation theory and VCG theory to connect the two types of experiments and allow prediction of how various types of sur faces may induce the heterogeneous nucleation in various solvents. A v ariety of examples are discussed that illuminate the important surface properties relevant to heterogeneous nucleation. This approach allows a rational design of surfaces to either promote or inhibit precipitat e formation.