Nucleation and growth heterogeneous

Campbell GA, Rasmussen DH (1994) Controlling heterogeneous nucleation and growth of foams. US Patent 5,358,675... 

This is the Gibbs-Wulff theorem as generalized by Kaischew for a crystal in contact with a substrate, i.e., for the case of heterogeneous nucleation and growth. Relation (4.10) allows the construction of the equilibrium form of a crystal ... 

The literature data on kinetics and mechanisms of BaTiOs formation under hydrothermal conditions are contradictory. In general, the precursor of Ba is completely soluble in aqueous solutions, while the Ti precursor usually forms solid gel-like phases with low solubility. Since Ba + is not a gel forming ion, it initially adsorbs on the particles surface and dissolves in the gel of titanium compounds, destroying Ti-O-Ti bonds. This is accompanied by dehydration, followed by crystallization of perovskite phase via heterogeneous nucleation and growth [82, 83, 89-93]. 

Considerable interest in preparation of oriented films such as in the review by Brinker is apparent [11]. Much of the work involves gas phase preparation from methods like chemical vapor deposition (CVD). However, solution phase sol-gel methods were also recently used in many studies. Heterogeneous nucleation and growth on preorganized modified substrates takes away the need to use single crystals. Hydrothermal alteration routes were also summarized [11]. 

We first demonstrated that avoiding direct stirring of the HA-urea mineral stock solution, which promotes homogeneous precipitation of HA across the solution, is essential in achieving the desired heterogeneous nucleation and growth of CP on the in situ generated acidic gel surface. 

In many practical cases of corrosion, the anodic dissolution takes place on a surface partially or totally covered by thick (order of micrometers) solid layers grown by several possible mechanisms (heterogeneous nucleation and growth, dissolution-reprecipitation) and usually regarded as porous. Until the past decade, the mechanism by which this layer interferes, with the anodic dissolution, and particularly the transport phenomena, remained poorly understood. The last developments deal with iron and copper in FFCl solutions and take advantage of steady-state RDE and RRDE associated with AC impedance (EIS and EHD) techniques. Mass transport and solution chemistry [169,170] let to a dissolution model [171] in which the electrochemical monoelectronic surface step... 

Corman et al., 1997). At present, two different mechanisms have been proposed to explain the reaction of liquid silicon with carbon. One considers the heterogeneous nucleation and growth of SiC which leads to the formation of a continuous SiC layer. However, the further growth of which is limited by the diffusivity of carbon and Si through SiC. In the second mechanism, the formation of SiC is deemed to proceed by a soluhon precipitation process (Fitzer et al., 1986 Li et al., 1996 Pampuch et al., 1986 Ness et al., 1986). 

The successful synthesis and resolution of a chiral thiol attached to a cyclic phosphate unit (38), that eontained a C-stereogenic center, allowed the preparation of chiral self-assembled monolayers on gold. The monolayers were used to promote the heterogeneous nucleation and growth of erystals from nonaqueous solutions of an organie molecule (the parent phencyphos) of similar structure to the compound present in the monolayer (Scheme 13). °... 

---