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Spectral Absorption of Unpolarized Light Through Nano-Materials in the Absence of a Magnetic Field

Domenii publicaţii > Fizica + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Ioan LUMINOSU, Dusan Popov, Ioan ZAHARIE

Editorial: Science of Sintering, 40(3), p.223-234, 2008.

Rezumat:

A study of optical properties, such as light absorption, of a colloidal nano-material, provides information on the biphasic, solid – liquid system microstructure. The nano-material under study is a magnetic liquid (ferrofluid). The disperser agent is petroleum mineral oil and the dispersed material is a brown spar powder (nano-particles). The stabilizer is oleic acid. Light absorption through ferrofluid samples reveals the tendency of solid particles in a colloidal solution to form aggregates. The paper emphasizes the linear dependence between the spectral absorption coefficient, concentration and wavelength. The aggregates cause deviations of the extinction coefficient from values according to the Bouger-Lambert-Beer law. Fe3O4 aggregates sized 58.76 nm are formed in the system. The average number of nano-particles forming aggregates is 6. The magnetic liquid to be studied is secure stable and, thus, trustful in technological and biological applications.

Cuvinte cheie: aggregates, absorption, biphasic, colloidal, extinction