سال انتشار: ۱۳۸۷

محل انتشار: دومین کنگره بین المللی علوم و فناوری نانو

تعداد صفحات: ۲

نویسنده(ها):

E.leila hossein saeedi – Department of chemical engineering,University of Semnan, Semnan,Iran
a Mansoor Jahangiri. – Department of chemical engineering,University of Semnan,Semnan,Iran

چکیده:

Surfactants or Surface Active Agents are used and fined a very large number of applications in different industries. They have a hydrophilic head group and a hydrophobic tail in the molecule which lie between two liquid phases (e.g. W/O) with different order of polarity and hydrogenous connections, so reduce the interfacial surface tension. They increase biological activity in three wayes: 1: They have effective role to release absorped hydrocarbonic pollutants at organic compounds. 2: Reduce surface tension, so release the arrested droplets between the pores. 3: Increasing the surface area for microbial connection. Surfactants can be classified to anionic, cationic, non-ionic and amphoteric based on hydrophilic head. They can be used as emulsifier or solvent , hence, reduce surface tension by dissolving in water and affect the physical and chemical properties.Surfactants have a major role in various industries such as oil , gas and petrochemical , food, pharmaceutical , special practical applications , e.g. detergents, softeners, emulsifires, soil remediation, agriculturals , etc.[1]nano-emulsions with droplet size in the nanometric scale typically in the range 20–۲۰۰ nm , appear transparent or translucent . The very small droplet size causes a large reduction in the gravity force and the Brownian motion , consequently , prevents creaming or sedimentation , flocculation of the droplets and also prevent their coalescence .They can penetrate through the ‘rough’ skin surface , so deliver active ingredients and enhance penetration of actives . Wetting, spreading and penetration may be also enhanced as a result of the low surface tension of the whole system and the low interfacial tension of the O/W droplets . surfactants play major roles in break-up of droplets and formation of stable droplets which In the absence of surfactants, the interface cannot withstand a tangential stress.[2,3,5,6