Colloids growth mechanism

Nancollas, G.H. and Reddy, M.M., 1971. The crystallization of calcium caronate. II Calcite growth mechanism. Journal of Colloid and Interfacial Science, 37, 824-833. 

Dai, S Liu, Y. and Lu, Y. (2010) Preparation of Eu3+ doped (Y,Gd)203 flowers from (Y.GdjflCO ) vn - jO flowerlike precursors microwave hydrothermal synthesis, growth mechanism and luminescence property. Journal of Colloid and Interface Science, 349, 34-40. 

For the reaction sol itself, a degree of agglomeration of sub-colloidal or colloidal amorphous particles seems very probable. However, a zeolite or zeotype growth mechanism based upon the aggregation of amorphous with crystalline particles [126], or the agglomeration of non-viable nuclei with other growing nuclei [128], is more problematic. Some form of... 

In the case of CdS, the ion-by-ion process is mainly considered as an explanation of the formation of adherent, specular layers, even in the presence of colloids in the bath [11]. This is probably the growth mechanism involved in the formation of the compact, adherent, inner CdS layer as discussed in sect. 4.3. At longer reaction times the incorporation of colloids, formed in parallel in solution, gives rise to a porous and less adherent outer layer [30]. 

In this paper we have tried to present the chemical and mechanistic aspects of chemical bath deposition of chalcogenide compounds as they appear both in the recent literature and also in older studies dealing with hydrolysis of chalcogenide precursors. A better account of these aspects gives clues to understanding the properties of the films such as the dependence of composition on solution composition and competitive precipitation processes, and the dependence of structure on competition between atom-by-atom and colloidal growth deposition mechanisms. 

S.H. Lee, Y.-S. Her, and E. Matijevic Preparation and Growth Mechanism of Uniform Colloidal Copper Compounds by the Controlled Double-Jet Precipitation. J. Colloid Interface Sci., 186, 193-202 (1997). 

Direct measurement of the adsorbed particles has proven difficult because of their weak binding to the surface. Nevertheless, the adsorbed colloidal particles have been detected by ion microprobe analysis [8], atomic force microscopy (AFM) [9, 10] and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) [10]. AFM results ofVan Roy and coworkers ]10] are shown in Fig. 3, along with their proposed nucleation and growth mechanism on the aluminum surface. These results demonstrate that under the conditions of these experiments, the adsorbed particles are flat with 7 to 8 nm thickness and 100 to 300 nm in diameter. According... 

Another explanation of the phosphate effect is possible phosphate-Mn(IV) interactions in aqueous phase. When chlorinated ethylenes are oxidized by Mn04, soluble Mn(IV) forms before any colloids. The existence of the soluble Mn(IV) has been reported by many researchers 16, 17). Phosphate ion can react with soluble Mn(IV) species and reduce the formation of die colloid. The process is probably involved with the formation of a phosphate-Mn(IV) conqilex. As the conqilex forms, it keeps the Mn(IV) in the aqueous phase without forming colloids. Eventually, colloids and prec itates will be produced when the capacity of the phosphate effect has reached its limit This mechanism is in agreement widi our observation in the colloid growth experiments. 

Tirado-Miranda, M., Schmitt, A., CaUqas-Femandez, J. and Femandez-Barbero, A. (1999). Colloidal clusters with finite binding energies fractal structure and growth mechanism. Langmuir, 15, 3437—3444. 

Figure 1.6 Schematic of colloidal syntheses of Au nanospheres and nanorods. Different surfactants are used to cap surfaces (or crystallographic facets) of crystal seed, resulting in altered growth mechanisms and leading to two geometries of Au nanoparticle.

Approaching the formation of colloids from the other end of the size range involves one of several growth mechanisms. Such processes are commonly employed for the production of dispersions and aerosols, and less commonly in the production of emulsions. Typical examples of important condensation processes include fog formation (both water and chemical), silver halide emulsions (really dispersions) for use in photographic products, crystallization processes, colloidal silica, latex polymers, etc. 

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