Abstract

RODRIGUEZ-RUIZ, Johana; MEZA-FUENTES, Edgardo  and  AZEVEDO ESPERIDIAO, Maria Cecília. INTERFACIAL PROPERTIES OF SURFACTANT PDMS-PEG-MALEIC ANHYDRIDE-FUMARIC ACID (PDMS-PEG-AM-AF) IN AQUEOUS SOLUTION. Rev.Colomb.Quim. [online]. 2012, vol.41, n.1, pp.61-74. ISSN 0120-2804.

In this work the interfacial properties in aqueous solution of surfactant of si-licon PDMS-ester type containing PEG, anhydride maleic and fumaric acid had been determined. In order to study the interfacial properties tensiometry and spectroscopy UV-VIS techniques were used. The surfactant in aqueous solution showed a complex behavior and this is dependent on the concentration. This surfactant was showed an abrupt change in surface tension curve as a function of concentration, leading to reduced sur-face tension of water to 48.9 mN/m in the CMC. The concentration of surfac-tant in the CMC was 1032 mg/L. The effciency of the PDMS-ester surfactant was calculated as pC₂₀ and determined as the concentration of surfactant re-quired to achieve a decrease in surface tension up 20mN/m. The value of C20 obtained was 213 mg/L (1.554 x10^-5 mol/L) (pC20 = 4.81). This concentra-tion serves as an indicator of the eff-ciency of adsorption of the surfactant, since the reduction of surface tension of the surfactant solution depends on the substitution of molecules at the interfa-ce solution / vapor.

Keywords : Silicon; surfactant; interfacial properties; Critical micellar concentration.

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