Silicates, colloidal

Calcium silicate Colloidal silicon dioxide Magnesium carbonate Magnesium trisilicate Starch Talc... 

Solubility. An important aspect of silica chemistry concerns the silica— water system. The interaction of the various forms of silica with water has geological significance and is applied in steam-power engineering where the volatilization of silica and its deposition on turbine blades may occur (see Power GENERATION), in the production of synthetic quartz crystals by hydrothermal processes (qv), and in the preparation of commercially important soluble silicates, colloidal silica, and silica gel. 

The results of additional experiments conducted with 85Sr and 137Cs spikes are shown in Figure 4. The well known sorption characteristics of bentonite for Sr and Cs ions is apparent (7). The sorption properties of bentonite are reduced at low pH, which is consistent with an electrostatic concept. 137Cs sorption on the iron silicate colloids is considerably less than that observed with bentonite, even though the colloid zeta potentials are similar, which suggests that mechanisms other than simple electrostatic concepts may be involved. Also, the linear trend of data for Sr in iron silicate systems is considered to represent precipitation rather than sorption. 

V90 39 1 P 64 h Cancer brachytherapy (as silicate colloid) to relieve arthritis pain in larger... 

Silica gel could be prepared via the gelation of silica sol. The process for the formation of water-containing uniform gel from spherical silical colloidal particles is very fast. It is known that there is adhesive force on the surface of spherical silica collodial particles, which could lead to the aggregation of these particles. This process could be described as below. 

Silicsol is a commercial product introduced in Europe this past decade. It is described as an activated silica liquor with a calcium-based reagent. As opposed to sodium silicate (colloidal silica particles dispersed in soda), silicsol is claimed to be a true solution. Viscosity and penetrability are similar to sodium silicate, but the reaction is different, resulting in a stronger end product more resistant to creep. There is no syneresis associated with silicsol. 

Very hard coatings can probably be made by applying the gel-forming liquid mixture of potassium silicate, colloidal silica, and setting agent developed by Shoup (Chapter 2, Refs, 97, 98). 

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