Thixotropic gels

A useful property of the red seaweed extracts is their abiUty to form gels with water and milk. Kappa-carrageenan reacts with milk protein micelles, particularly kappa-casein micelles. The thickening effect of kappa-carrageenan in milk is 5—10 times greater than it is in water at a concentration of 0.025% in milk, a weak thixotropic gel is formed. 

Langmuir, . (1938) The role of the repulsive and attractive forces in the formation of tactoids, thixotropic gels, protein crystals and coacer-vates. J. Chem. Phys. 6 873-896... 

Thixotropic gels are also useful as propellants for rocket applications. These are commonly called thixotropes or gels. Normal fuels and oxidizers are converted into thioxotropes by the addition of a small quantity of a gelling agent in order to ensure uniform suspension of solid additives (usually metal additives) during storage. It is reported that if very finely pulverized particles of beryllium or aluminum are suspended in the liquid fuel, it is possible to increase the specific impulse substantially. 

Thixotropic gels (TPGS) of mono- and diglycerides have been used as carriers forsolid dispersions. In the development of a hard gelatin capsule formulation of a poorly water-soluble drug, propantheline bromide, the drug substance was Lrst dissolved in Miglyol 829 and the solution was then converted... 

Liquid concentrates are much like latex paint but range in consistency from liquids to thixotropic gels and pastes. The major advantage of a liquid form is distribution efficiency. 

Comments mixtures of microcrystalline cellulose and carboxymethylcellulose sodium that are dispersible in water and produce thixotropic gels are suitable as suspending vehicles in pharmaceutical formulations. The amount of carboxymethylcellulose present can vary between 8.3% and 18.8% w/w depending upon the grade of material. 

Okor RS. The effect of phenol on the electrolyte flocculation of certain polymeric dispersions to thixotropic gels. Pharm Res 1993 10 220-222. 

WO 89/04359 (1989) [67] Donker (Unilever) Thixotropic gel with alkyl phosphate, phosphonate, sulfate, or sulfonate Improved stability against phase separation... 

U.S. 4226736 Bush et al. (Drackett) Thixotropic gel Reduced cup leakage low foaming... 

In the gelled electrolyte battery, the sulfuric acid electrolyte has been immobilized by a thixotropic gel. This is made by mixing an inorganic powder such as silicon dioxide [7631-86-9], Si02, with the acid (3). Other cells, such as the one shown in Figure 3, use a highly absorbent separator to immobilize... 

Clays of the montmorillonite family are lamellar aluminosificates [46] used in many industrial processes and in products such as paints, softeners, and composite materials [47]. They swell when brought into contact with water, which is due to the insertion of water molecules between the sheets. Complete exfoliation can be induced leading to dispersions of disk-like particles of 10 A thickness and 300-3000 A in diameter, depending on the variety of clay used. These clay platelets bear a rather large surface electrical charge so that electrostatic interactions between them must be considered and are actually responsible for the colloidal stability of these dispersions. These suspensions have been widely studied as model colloids and also because they form physical thixotropic gels. 

Crystals from benzene + petr ether, mp 151 -152. [n]g +45 (chloroform). Sol in ether, methanol, benzene, chloro -form, peanut oil. cottonseed oil, com nit, sesame oil. The limit of soly in the oils is about 400 tng/ml. Thixotropic gels may be prepd by adding aluminum monostearate to the oil solns. 

The hydrophobized clay can be directly dispersed in monomers and subjected to miniemulsion polymerization. Due to the formation of thixotropic gels and therefore high viscosities, the concentration of clay in the monomer is limited to about 4% [121], Tong et al. [126] could successfully disperse 30 wt% of modified saponite in styrene by modifying the clay with (ar-vinylbenzyl)trimethylammonium chloride (VBTAC) which is used as comonomer for styrene or acrylates. The dispersion in styrene was of low viscosity and therefore suitable for the miniemulsification process. 

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