Agglomeration, of colloids

Flocculation Agglomeration of colloidal material by adding a chemical that causes the colloidal particles to produce larger particles. 

As can be seen from Figure 2 the adsorption branch of this isotherm exhibits two distinct steps that reflect the capillary condensation inside smaller or larger mesopores at relative pressures about 0.79 and 0.9, respectively. The condensation in the relative pressure range of 0.9S-0.99S reflects condensation in secondary mesopores or small macropores, which resulted from the imprinting of agglomerates of colloidal particles. To our knowledge, this kind of isotherm has not been reported for porous carbon materials. The pore size distribution for this mesoporous carbon shown in Figure 3 exhibits two distinct peaks located about 11 nm and 24 nm, which correspond to the particle size of Bindzil 30/360 and Ludox AS-40 colloidal silicas, respectively. 

The peptization capabilities of polyphosphates depend on their sorption on aluminosilicates and colloidal particles of hydrated oxides of iron, aluminium and manganese. In practice, this causes problems in water treatment by coagulation when already rather low concentrations of polyphosphates can cause improper agglomeration of colloidal particles into sedimentable floccules. 

At pH less than 7 or 8, silica sols are not stable. Agglomerates of colloidal particles form and the silica sol can gel. This effect grows more pronounced as the concentration of the sol increases. In very dilute sols, low pH can be tolerated but in general should be avoided. 

Since the beginning of colloids science, however it is also known that the agglomeration of colloids and dispersed particles can be prevented or controlled by stabilization [8]. The attractive interactions between the colloidal particles, caused by van-der-Waals forces, need to be compensated by repulsive interactions. The latter can be based either on electrostatic repulsion due to same-sign surface charges (electrostatic stabilization), or on repulsion via a polymer shell formed through adsorption of polymers to the particle surface (steric stabilization, in presence of polyelectrolytes termed electrosteric stabilization due to additional charged-induced repulsion) [9, 10]. The stabilization by control of the interaction forces between colloidal particles has been in the focus of extensive research efforts. Already... 

The sol-gel process is a wet-chemical technique used for the fabrication of both glassy and ceramic materials. In this process, the sol (or solution) evolves gradually toward the formation of a gel-like network containing both a liquid phase and a solid phase. In other words the sol-gel process is the formation of an oxide network through polycondensation reactions of a molecular precursor in a liquid. A sol is a stable dispersion of colloidal particles or polymers in a solvent. These particles may be amorphous or crystalline. A gel consists of a three-dimensional continuous network, which encloses a liquid phase. In a colloidal gel, the network is built from agglomeration of colloidal particles... 

Features For low-free electrolyte content and low conductivity tec. tor systems where free electrolyte tends to promote gelation and agglomeration of colloidal suspension... 

It also has been shown that the control of the reaction is a to the material property tailoring. It is of special interest that even with colloids veiy stable links between inoiganic and organic phases can be provided, thus prevoiting agglomeration of colloidal particles, which is an indispenable requirement for using these nanocomposites for optical applications. 

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