Emulsions Vegetable particle sizing

The self-emulsifying behaviour of a binary nonlonlc surfactant vegetable oil mixture has been shown to be dependant on both temperature and surfactant concentration. The quality of the resulting emulsions as assessed by particle size analysis showed that manipulation of these parameters can result In emulsion formulations of controlled droplet size and hence surface area. Such considerations are Important when the partition of lipophilic drugs Into aqueous phases and drug release rates are considered. 

Elemental sulfur is an acaridde and fungicide widely used on orchard, ornamental, vegetable, grain, and other crops. It is prepared as dust in various particle sizes and applied as such, or it is formulated with various minerals to improve flowability, or is applied as an aqueous emulsion or wettable powder. 

Colloids are classified according to the phases of the substances involved (Table 15.10). A colloid that is a suspension of solids in a liquid is called a sol, and a suspension of one liquid in another is called an emulsion. For example, muddy water is a sol in which tiny flakes of clay are dispersed in water mayonnaise is an emulsion in which small droplets of water are suspended in vegetable oil. Photographic emulsions also contain solid colloidal particles of light-sensitive materials such as silver bromide. Foams are suspensions of a gas in a liquid or solid. Foam rubber, Styrofoam, soapsuds, and aerogels are foams. Zeolites (Box 13.4) are a type of solid foam in which the openings in the solid are comparable in size to molecules. 

Other water-borne coatings include water-soluble emulsions, dispersions, and latex resins. Water-soluble resins are rare because most resins derived from vegetable oils are insoluble in water. The true emulsions are based on the emulsification of the oil or alkyd through either the action of a surfactant or a resin that has a surfactantlike character. The alkyd emulsions are readily prepared and can be used for OEM coatings and architectural applications. The submicron size droplets are stabilized by the thickeners (El-Aasser Sudol, 2004 Landfester, 2005 Landfester et al., 2004 Tsavalas et al., 2004 Weissenborn Motiejauskaite, 2000a,b). In dispersions, the resin is a solid and is dispersed in water. The latex resin is usually vinyl acetate, styrene, acrylates, or methacrylates radically copolymerized in a micelle to form particles 0.1 pm in diameter (Bloom et al., 2005 Brister et al., 2000 Jiratumnukul Van De Mark, 2000 Thames et al., 2005). 

In addition, emulsion polymerizations exhibit promising benefits and the possibility for efficient control of the composition and size of particles. As a result, this causes these processes to exhibit excellent results in the polymerization of monomers with low reactivity, such as vegetable oils and their derivatives [21,22]. Apropos to the production of polymer/inorganic hybrid nanoparticles, pertain promising results of products intended for medical/pharmaceutical area, particularly magnetic nanoparticles used for the induction of controlled hyperthermia procedures in treatment of... 

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