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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 12: Poster: Nanoparticles and Composite Materials

CPP 12.25: Poster

Monday, March 11, 2013, 17:30–19:30, Poster C

Surfactant modified silica particles at the air/water interface — •Adrian Carl, Anne Bannuscher, and Regine von Klitzing — TU Berlin, Straße des 17. Juni 124, Institut für Physikalische Chemie, Stranski Laboratorium

The combination of nanoparticles and suitable surfactants has been shown to increase aqueous foam stability compared to the same system without nanoparticles. The origin of the increased stability is not fully resolved, yet. Unmodified, hydrophilic nanoparticles show no attachment to the water/air interface. On addition of surfactant, the particles are rendered hydrophobic and adsorb to the interface. In equlibrium, a specific surface coverage is obtained. At the interface, a comparatively rigid particle layer, withstanding compression, is formed. The location within the interface is governed by the particle's wetting properties which are expressed by the contact angle.

We conduct x-ray reflectivity (XRR) measurements to characterize the equilibrium state of the adsorbed particle layer. The results are related to surfactant adsorption isotherms and the adsorption kinetics are obtained from dynamic surface tension measurements.