Colloids gelatins

And since high uric acid levels were associated with migraine as well, there appeared to be a positive relation between acid in the blood and blood pressure. Finally, Haig had already observed that test tube solutions of urates could be chemically manipulated to form gelatinous colloids, and supposed it was "quite possible" a like phenomenon might occur in the blood. 

Gelatin colloids consist of cross-Unked peptide chains obtained from collagen. They are employed for blood replacement, but not for hemodilution, in circulatory disturbances. 

Gelatin colloids = cross-linked peptide chains MW 35 000... 

Fig. 63.—Phase diagram of the gelatin-colloidal starch-water system I, 45°C II, 35°C III, points of initial mechanical mixtures. (Reprinted with permission from V. Ya. Grinberg, V. B. Tolstoguzov, and G. L. Slonimskii, Kolloid. Zh., 33 (1971) 666-669.)...

Rodin, V.V. and Izmailova, V.N. NMR method in the study of the interfacial adsorption layer of gelatin. Colloids Surfaces A, 106, 95,1996. 

Toledan0,0. and Magdassi, S. (1998) Emulsification and foaming properties of hydrophobicaUy modified gelatin. /. Colloid Interf. Sci, 200,235. 

All hydrophilic colloids possess some degree of protective action and gelatin, starch and casein are used commercially for this purpose. 

If a dilute acid is added to this solution, a white gelatinous precipitate of the hydrated tin(IV) oxide is obtained. It was once thought that this was an acid and several formulae were suggested. However, it now seems likely that all these are different forms of the hydrated oxide, the differences arising from differences in particle size and degree of hydration. When some varieties of the hydrated tin(IV) oxide dissolve in hydrochloric acid, this is really a breaking up of the particles to form a colloidal solution—a phenomenon known as peptisation. 

Hydrolysis of solutions of Ti(IV) salts leads to precipitation of a hydrated titanium dioxide. The composition and properties of this product depend critically on the precipitation conditions, including the reactant concentration, temperature, pH, and choice of the salt (46—49). At room temperature, a voluminous and gelatinous precipitate forms. This has been referred to as orthotitanic acid [20338-08-3] and has been represented by the nominal formula Ti02 2H20 (Ti(OH). The gelatinous precipitate either redissolves or peptizes to a colloidal suspension ia dilute hydrochloric or nitric acids. If the suspension is boiled, or if precipitation is from hot solutions, a less-hydrated oxide forms. This has been referred to as metatitanic acid [12026-28-7] nominal formula Ti02 H2O (TiO(OH)2). The latter precipitate is more difficult to dissolve ia acid and is only soluble ia concentrated sulfuric acid or hydrofluoric acid. 

A typical recipe for batch emulsion polymerization is shown in Table 13. A reaction time of 7—8 h at 30°C is requited for 95—98% conversion. A latex is produced with an average particle diameter of 100—150 nm. Other modifying ingredients may be present, eg, other colloidal protective agents such as gelatin or carboxymethylcellulose, initiator activators such as redox types, chelates, plasticizers, stabilizers, and chain-transfer agents. 

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