Homogenized colloidal suspension

A homogeneous aqueous colloidal suspension of chemically crosslinked GO sheets was generated by addition of polyallylamine to an aqueous suspension of GO sheets followed by sonication of the mixture Production of a homogeneous colloidal suspension of crosslinked GO sheets... 

The precipitation methods always have the disadvantage that the stoichiometry of the precipitate (s) may not be exact if one or more ions are left in solution. The solgel method overcomes this because the reactants never precipitate out. First, a concentrated solution or colloidal suspension of the reactants, the sol , is prepared, which is then concentrated or matured to form the gel . This homogeneous gel is then heat-treated to form the product. The main steps in the sol-gel process are outlined in Figure 3.3. 

This means that an aqueous salt solution should not be viewed as a homogeneous liquid with a modified inter-molecular interaction, but rather as a colloidal suspension of inert particles in pure liquid water, with the particles formed by the ions and their first solvation shells. Following this view of an aqueous salt solution, the viscosity at low concentration can be described by the Einstein equation [19] ... 

Colloidal suspensions can be classified in a number of ways. Most obvious is by the phase of the homogeneous dispersing medium and that of the dispersed particles, as shown in Table 2. 

Suspension of finely ground hard fat or emulsifier in a cool liquid oil with subsequent comminution using a homogenizer, colloid mill, or shear pump. 

The internal chemical coupling C-+C includes homogeneous reactions in a gaseous or aqueous phase, and transport processes driven by chemical forces, such as molecular or ionic diffusion, and those heterogeneous processes related to it that do not involve large-scale transport for example, certain types of surface reactions or interactions between particles in colloidal suspensions (O Melia, Chapter 16, this volume) that are driven primarily by electrochemical forces fall in the class of C->C interactions. 

In this experience, the colloid suspension was introduced into a reactor of volume equal to 50 mL and stirred to ensure homogeneity. At time zero, the polymer solution was injected at constant rate and periodically the corresponding volume of the suspension was collected for a certain time to determine the aggregate mass characteristics and to start fragmentation experiments by immersion of these aggregate samples in the polymer solution of concentration C /30. This procedure allows the surface coverage T(f) to be a linear function of the injection time t due to fast total adsorption of the injected polymer. The variations with time of the average masses N(t) and... 

A colloidal suspension also consists of solute particles distributed throughout a solvent. However, the distribution is not completely homogeneous, owing to the size of the colloidal particles. Particles with diameters of 1 X 10 m (1 nm) to 2 X 10 m (200 nm) are colloids. Particles smaller than 1 nm are solution particles those larger than 200 nm are precipitates (solid in contact with solvent). 

Sol-gel technology allows better mixing of the ceramic components at the molecular level, and hence yields more homogeneous ceramics, because the ions are mixed while in solution. In the sol-gel process, a solution of an organometallic compound is hydrolyzed to produce a sol, a colloidal suspension of a sofid in a fiquid. Typically the solution is a metal alkoxide such as tetramethoxysilane in an alcohol solvent. The sol forms when the individual formula units polymerize (link together to form chains and net-... 

The Ziegler-Natta catalysts can be sub-divided into two groups (1) heterogeneous insoluble catalysts, and (2) homogeneous, or soluble ones. At times, however, it is difficult to distinguish between the two. For instance, it may be hard to determine whether a particular catalyst is truly in solution or merely in a form of a very fine colloidal suspension (and in fact heterogeneous). 

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