Colloid aggregation process

Method for synthesis of monodisperse spherical-like manganese carbonate (MnCOs) particles by colloidal aggregation process is developed. Hollow polyelectrolyte capsules have been prepared by means of layer-by-layer absorption of charged polyelectrolytes on microsized MnCOs particles with the subsequent decomposition of a micrometer nucleus. The use of inorganic templates is a way for clean capsules fabrication. The manganese carbonate particles and capsules obtained were investigated by SEM, SFM, XRD, and confocal fluorescent microscopy. 

Based on the application of the established theory of colloid stability of water treatment particles [8,85-88], the colloidal particles in untreated water are attached to one another by van der waals forces and, therefore, always tend to aggregate unless kept apart by electrostatic repulsion forces arising from the presence of electrical charges on the particles. The aggregation process... 

An electron microscopy study by Mullen et al. (1989) showed that Cd2+, Cu2+ and La3+ accumulated on the cell surface of Bacillus cereus, B. subtilis, E. coli and Pseudomonas aeruginosa as needle-like, crystalline precipitates, while Ag+ precipitated as discrete colloidal aggregates at the cell surface and occasionally in the cytoplasm. The needle-like and hexagonal precipitates were also found for the biosorption of Ni2+ on the cell surface of P. fluorescens 4F39 at pH 9 and it was suggested as a microprecipitation process that followed on ion exchange (Lopez et al. 2000). 

Dickinson, E. (1997). Aggregation processes, particle interactions and colloidal structure. In Dickinson, E., Bergenstahl, B. (Eds). Food Colloids Proteins, Lipids and Polysaccharides, Cambridge, UK Royal Society of Chemistry, pp. 107-126. 

Su, R., Qi, W., He, Z., Zhang, Y. Jin, F. (2008). Multilevel structural nature and interactions of bovine serum albumin during heat-induced aggregation process. Food Hydro-colloids, 22, 995-1005... 

Darier Goudet (Ref 25) describe the prepn with a min risk of expln by effecting the reaction within the interstices of a porous absorbent material which is inert and maintains the expl crysts separate from each other. Taylor Rinkenbach (Ref 27) prepd Ag azide in the pure state, as white colloidal aggregates, by mixing fairly coned solns of AgNOj and NaNs. The colloidal prod was more stable and less sensitive than the crysts. Meissner (Ref 30) described an app for the prepn of Ag azide by a continuous process and Stettbacher (Ref 73) detailed a recent lab procedure for its prepn Explosive Properties ... 

This chapter will focus on the modeling of physical colloidal interactions and will present the conceptual and methodological approach to quantifying the physical aggregation process by a variety of techniques. Only brief consideration will be given to stability considerations, which are of utmost importance... 

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