Aqueous gelatin

Subtractive dye precursors (couplers) that could be immobilized in each of the silver containing layers were sought, so that dye formation in all layers could proceed simultaneously rather than successively. The first of these to be commercialized were in Agfacolor Neue and Ansco Color films, introduced soon after Kodachrome film. These reversal working films contained colorless couplers that were immobilized (ballasted) by the attachment of long paraffinic chains. The addition of sulfonic or carboxyUc acid groups provided the necessary hydrophilicity to make them dispersible as micelles in aqueous gelatin. 

Bohidar et al. 1998, realized studies of Sol and Gel state properties of aqueous gelatin solutions of concentrations 4%, 6%, 8% and 10% (w/v) were investigated through dielectric relaxation studies done at various temperatures in the range from 20 to 60°C carried out over a frequency range 20Hz-10MHz and no relaxation of any nature was observed. 

Borchard W., Colfen H., Kisters D., Straatmann A. 2002. Evidence for phase transitions of aqueous gelatin gels in a centrifugal field. Progress in Colloid Polymers Science 119,101-112. 

Y. A. Antonov, P. Van Puyvelde, P. Moldenaers 2004, (Effect of shear flow on the phase behavior of an aqueous gelatin-dextran emulsion), Biomacromolecules 5, 276. 

Methods of fixing the volatile aroma and flavor compounds separately from the instant coffee powder have been developed. The volatile mixture can be mixed with aqueous gelatin or gum arabic and spray dried. The oily droplets of the flavor and aroma compounds are coated with gelatin or gum arabic in a dry lattice. This powder can be mixed in with instant coffee powder and is relatively stable in the presence of air. Emulsification with sugar is also a highly effective way of trapping and preserving coffee volatiles, but is of limited use for instant coffees. 

Djabourov, M., Leblond, J. and Papon, P. (1988) Gelation of aqueous gelatin solutions. 1. Structural investigation. Journal of Physics France, 49, 319-332. 

Gelatin-PMMA composite materials can also be prepared via the HIPE pathway [187]. Concentrated emulsions of methyl methacrylate in aqueous gelatin/surfactant solutions, upon polymerisation at 50°C, yielded composite membrane materials. The gelatin lends considerable stability to the emulsions, which will not form in its absence. The membranes swelled in water and certain... 

Mohanty, B., Bohidar, H.B. (2003). Systematic of alcohol-induced simple coacervation in aqueous gelatin solutions. Biomacromolecules, 4, 1080-1086. 

The emulsions used in this work were composed of the suspension of AgBr grains in aqueous gelatin solution, and were prepared by the controlled double-jet precipitation method. The edge lengths... 

Lyophilic colloids can also be desolvated (and precipitated if the electric double layer interaction is sufficiently small) by the addition of non-electrolytes, such as acetone or alcohol to aqueous gelatin solution and petrol ether to a solution of rubber in benzene. 

In a microencapsulation method, the encapsulate—usually an oil, flavor, enzyme, or medicinal—is emulsified in a dilute aqueous gelatin sol, a polysaccharide is added, and conditions are adjusted to favor coacervation. The encapsulate should not be truly soluble in the solvent or the cosolutes and the cosolutes should be differentially soluble in the liquid solvent. As much as 60-98% of the labile substance may be harvested by microencapsulation to yield microcapsules in the form of a free-flowing powder (Sirine, 1968). 

Figure 5 Aging of an aqueous, gelatinized starch dispersion showing phase separation with time (10 days).

To manufacture the shells, pairs of molds, for the body and the cap, are dipped into an aqueous gelatin solution (25-30% w/w), which is maintained at about 50°C in a jacketed heating pan. As the pins are withdrawn, they are rotated to distribute the gelatin evenly and blasted with cool air to set the film. Drying is carried out by... 

The salt bridge contains an electrolyte such as KCI in an aqueous gelatinous medium to control the flow of K (aq) and Cr(aq) ions. When current is drawn from the cell, the electrodes are linked by an external wire to a load (examples include a light bulb or motor). Current (electrons) flows through the wire from anode to cathode as indicated and the spontaneous chemical cell reaction Zn(s) + Cu (aq) — Cu(s) + Zn (aq) occurs. 

ZAGORSKI, Z.P. Aqueous gelatine gels as the medium of pulse radiolysis , Radiat.Phys.Chem. 34 (1989) 839-847. 

A semibatch reaction crystallizer with a profiled bottom and/ or a draft tube was used by Stavek et al. (1988) to study the influence of hydrodynamic conditions on the controlled doublejet precipitation of silver chloride microcrystals. The crystallizer is a cylindrical vessel (14cm in diameter) equipped with four radial baffles and a six-pitched-blade impeller to provide good mixing. Silver nitrate and potassium chloride solutions were added at a constant rate to the crystallizer, which contained aqueous gelatin solution. The temperature and silver ion concentration in the crystallizer were controlled during the run. 

Several assessments of experimental data from continuously operated precipitators, utilizing the population balance (section 8.1.1), are of particular interest, e.g. the MSMPR studies on calcium carbonate by Baker and Ber-gougnou (1974), calcium sulphate hemihydrate in phosphoric acid (Sikdar, Ore and Moore, 1980) and silver bromide in aqueous gelatin suspension (Wey, Terwilliger and Gingello, 1980). 

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