Emulsion additives

The relative value of the two potentials reveals the destabdization action of salts added to the emulsion. Addition of an electrolyte to the continuous phase causes a reduction of the electric double-layer repulsion potential, whereas the van der Waals potential remains essentially unchanged. Hence, the reduced electric double-layer potential causes a corresponding reduction of the maximum in the total potential, and at a certain concentration of electrolyte the maximum barrier height is reduced to a level at which the stabdity is lost. 

Emulsion additives may also incorporate magnesium oxide-hydroxide slurries as part of the product. 

Emulsion additives (water droplet emulsions) also aid in the reduction of NOx gases (by perhaps 15%) by the lowering of excess air requirements. 

Other Emulsion Additives. In addition to chemical and spectral sensitizers, several other classes of chemical compounds are added to emulsions before coating. Additives are used to facilitate coating operations, e.g., surfactants (qv) and viscosity enhancers to reduce spontaneous development in unexposed regions, e.g., tetraazaindenes and inercaptutetiazoles and to reduce abrasion and permit high temperature processing, e.g., aldehydes. 

The O2 also could react with an organic agent such as gelatin or some emulsion additive to extract a hydrogen atom, forming hydrogen peroxide (84)... 

R Silver emulsion additive giving a black tone to the image and increasing the sensitivity 519... 

Of the various methods of latex preparation known and practiced, a variant of the emulsion-addition method was chosen for further investigation because the reaction temperature is easy to control and coagulum... 

To gain a better understanding of this phenomenon we followed the number of particles in the reactor with time during the monomer emulsion addition for three different distribution ratios of the anionic emulsifier. The ratios 40/60, 97/3, and 100/0 were chosen because they gave different particle sizes of the ultimate latex the first on the flat part of the curve in Figure 2, the second just in the bend, and the third on the... 

The particle size distribution of various latices, prepared via the above monomer emulsion addition technique, was determined with the aid of an ultracentrifuge. It was found to be invariably of the log-normal type, as shown in Figure 6, independent of the way the particles are formed. This illustrates that the agglomeration of particles during latex preparation, when the initial reactor charge contained more than 15% of the anionic emulsifier, is a random and not a selective process. 

Vinyl esters of trialkylacetic acid copolymerize randomly with vinyl acetate. Paint latices with a very low residual monomer content, based on vinyl acetate-W 911 copolymers, can be prepared reproducibly via a variant of the monomer emulsion addition technique, when a relatively large part of the anionic emulsifier is present in the initial reactor charge. 

The other ma]or olass of emulsion additives is that of stabilizers. In contrast to emulsifiers, stabilizers are non-surface active macromolecules which are added to emulsions in order to inorease the visoosity of the continuous phase, thus reducing the mobility of the droplets in order to prevent emulsification from ooalescence [32]. 

The non-Newtonian nature of emulsion-solids mixtures depends on the nature of the pure emulsions. Addition of solids to a highly shear-thinning emulsion also results in a shearthinning mixture. However, addition of solids to a fairly Newtonian bitumen emulsion results in a more complex mixture that can exhibit different non-Newtonian behaviors at different shear stress or shear rate. 

The techniques used for demulsification of a transport emulsion may include raising the temperature of the emulsion, addition of emulsionbreaking additives, addition of diluents to reduce the viscosity of the heavy crude oil, and the use of equipment designed to promote coalescence of the crude-oil droplets. Raising the temperature of the emulsion increases the... 

The addition of electrolyte or dmgs to intravenous fat emulsions is generally contraindicated because of the risk of destabilising the emulsion. Addition of cationic local anaesthetics reduces the electrophoretic mobility of the dispersed fat globules, and this contributes to instability. Minimum stability (and minimum zeta potential) is caused by addition to Intralipid of 3 x 10 mol dm CaCl2 and 2.5 X 10 mol dm NaCl, which are thus... 

Manufacturing Technique Hard Tissue Replacement Injection Molding Bicontinuous microemulsion Inverse microemulsion Emulsion Additives... 

Emulsion addition involves the metering of an emulsion prepared from part of the monomer, water and surfactant from the formulation. After beginning the reaction, the monomer emulsion is fed to the reaction mixture in a programmed manner. 

The most significant distinction between the two classes of semi-batch process is, therefore, that an emulsion addition process necessarily involves the addition of smfactant throughout the particle growth period during which monomer is added. In the strict definition of a monomer addition process, the surfactant is introduced completely at the outset of the polymerization however, it is more usual for surfactant to be added during the reaction (to ensure colloidal stability as the particles grow), but normally as a separate input stream. 

The choice of method for introducing the monomer to the reaction vessel can have significant effects upon the particle size and panicle size distribution of the latex produced [e.g. 56]. Consider the effects of monomer addition and emulsion addition processes when used vdth the same formulation. The surfactant concentration in the seed stage will be higher fw the monomer addition process because all of the surfactant is used in the seed stage, whoeas only pan can be used for the emulsion addition process since some surfactant is required to prepare... 

BYK 4B1 BYK -052 BYK -053 Perenol E1 Polyvinyl isobulyletier defoamer, altyd resin emulsions Addital XW376... 

Synonyms Hydrogen sulfate Polydextran sulfate Sulfuric acid, dextran ester Definition Sulfuric acid ester of dextran Uses Binder in cosmetics pharmaceuticals (treatment for hyperlipidemia and ulcers, artery factor agent, blood coagulant) biotech applies. (DNA hybridization) industrial applies, (photographic emulsion additive)... 

Al-Bagoury M, Yaacoub E.J (2004) Semicontinuous Emulsion Copolymerization of 3-0-methacryloyl-l,2 5,6-di-0-isopropylidene-a-D-glucofuranose (3-MDG) and Butyl Acrylate (BA) by Pre-emulsion Addition Technique. Europ. Polym. J. 40 2617-2627. 

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