Effects on dispersion stability

After all other conditions had been optimized, the effect of temperature during the adsorption step was studied again, particularly because the temperature reduction from 150° to 100 °C had no deleterious effect on dispersion stability. Adsorption of the block copolymer onto the titanium dioxide at room temperature would be easy to carry out in practical applications and might be worth even a sacrifice in dispersion stability. Figure 4 shows settling data of dispersions prepared in a Waring... 

Specific gravity is defined as the weight of pigment per unit volume relative to a standard, usually water. This property is important, because it can sometimes have an effect on dispersion stability. Pigments that are heavier than the vehicle in which they are dispersed are prone to settling. 

Carbon black grafting has a similar effect on dispersion stability (Figure 6.20)." Modified carbon black is substantially improved. The graphs show that... 

Carbon black grafting has a similar effect on dispersion stability (Figure... 

Interaction between hydroxypropylcellulose and surfactant and its effect on dispersion stability of kaoiinite suspension in an aqueous phase... 

The determination of the zeta potential of particles in a disperse system provides useful information concerning the sign and magnitude of the charge and its effect on the stability of the system (see Sec. II.B) [56, 206 208], It can be of value in the development of pharmaceutical suspensions, particularly if the... 

In this paper some of the current thinking in three closely-related areas is highlighted polymer adsorption the effect of polymer on the pairwise interaction between particles and the effect of polymers on dispersion stability. 

Vincent, B. Adv. Coll. Interface Sci. 4 (1974) 193. The effect of adsorbed polymers on dispersion stability. 

The dispersion polymerization system is composed of monomer, solvent, initiator, and stabilizer. The combination of monomer, solvent, and stabilizer is essential for particle preparation. That is to say, the stabilizer is chosen to meet the demand of the monomer and solvent. In any system, the stabilizer has affinity or cohesive strength for both the medium and the polymer particles. In a dispersion polymerization, the medium and polymer particles both are organic compounds. Therefore, it is not rational to rely on dispersion stabilization, which comes from the electrostatic repulsion force between particles. The stabilizer for dispersion polymerization that makes interfacial energy low must have affinity for particles due to the same quality and solvation at the surface of particles. It is desired that the stabilizer be a polymer that indicates a steric stabilization effect on the surface (5). 

However, solvent extraction has proven to be more effective. When a sample of 1 g MTS-W was dispersed in 50 mL of ethanol and refluxed for 12 hours. Elemental analysis showed that ca. 50% of the organic templates could be removed without any apparent effect on the stability of the mesostrucutre. We have also found that the mesostructured compounds are stable in concentrated HC1 solution. For example, when MTS-W was stirred in a 12M HC1 solution at room temperature for 12 hours, ca. 30% of the organic templates could be removed without collapsing the mesostructure or decomposing the inorganic walls. 

In future work we intend to study the effect of the composition of the block copolymers on dispersion stability more extensively. Preliminary results with graft copolymers have indicated that graft copolymers act as dispersants in essentially the same way as block copolymers when one type of sequence is carboxylated and the other type sequences are dissolved in the dispersion medium. 

Additional influences on dispersion stability beyond those accounted for by the DLVO theory, like surface hydration and steric effects, have received considerable attention over the past several decades [194,278],... 

Sc, Al, Th Zr", and Si, have been prepared according to the wetness impregnation method to investigate their effects on thermal stability of ceria. These impregnation methods are. of course, useful to synthesize ceria-based oxides supported on another oxides such as silica and alumina. The most advantage of the method is that highly dispersion is obtained. 

In many cases mixed electrolyte systems can he added to a latex either adventitiously or deliberately. Hieir effects on the stability of dispersions can best be summarized by Fig. 22. The axes of this figure are plotted as a percentage, so that the abscissa is the ccc value of salt 1 expressed as a percentage of its ccc value in the absence of the second salt salt 2 is expressed on a similar basis. Thus, the simplest possible case is additivity in... 

Suspensions of HTSC for the electrophoretic deposition of bismuth [403-409] and thallium [403] HTSC, various cuprates of rare-earth metals and barium [204, 407,410-414], and also silver HTSC [415,416] and PbO-HTSC [417] compositions have been used. These are prepared in acetone, acetonitrile, toluene, butanol, methylethylketone, or mixed solvents. They contain chemically pure materials (silver is introduced as AgaO) dispersed thoroughly, first mechanically and then in liquid) by ultrasonic treatment (in which case the particles became charged). The choice of solvent is by and large determined by its effect on the stability of the deposited oxide [417]. 

A study of column extraction of metals was carried out using pre-packed columns available from Polymer Laboratories (now a part of Varian, Inc.) [6]. Trace metals in these monomers would have a detrimental effect on the stability of anaerobic adhesive products and must be absent prior to use. The columns used are specially coated macroporous polystyrene products that are compatible with polar, non-polar, protic and aprotic solvents. They are designed to remove metals from solvents and monomers. The metal removing SPE product is approximately 45 pm and based on a mono-dispersed macroporous polymeric material. 

The treatment of micellar casein dispersions altered pH-heat stability profiles. At a pH up to 6.45, there was a negligible effect on heat stability, but stability to heat treatment at 140 °C was markedly improved when pH was increased to 7.1. In these systems, there was minimal intermolecular cross-linking between micelles (Mounsey et al., 2005). 

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