PROPIEDADES INTERFACIALES DEL SURFACTANTE PDMS-PEGANHIDRIDO MALEICO-ACIDO FUMARICO (PDMS-PEG-AM-AF) EN SOLUCION ACUOSA

Abstract

In this work the interfacial properties in aqueous solution of surfactant of silicon 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 surface tension of water to 48.9 mN/m in the CMC. The concentration of surfactant in the CMC was 1032 mg/L. The efciency of the PDMS-ester surfactant was calculated as pC20 and determined as the concentration of surfactant required 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 concentration serves as an indicator of the efciency of adsorption of the surfactant, since the reduction of surface tension of the surfactant solution depends on the substitution of molecules at the interface solution / vapor.