Dresden 2014 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 29: Colloids and Complex Liquids I

CPP 29.8: Vortrag

Mittwoch, 2. April 2014, 11:30–11:45, ZEU 114

Nanoparticle stabilized aqueous foams: Correlation with interfacial nanoparticle adsorption — •Adrian Carl, Anne Bannuscher, and Regine v. Klitzing — TU Berlin, Institut für Physikalische Chemie, Straße des 17. Juni 124, 10623 Berlin

Silica nanoparticles can become effective foam stabilizers when they are partially hydrophobized. Foams were prepared from dispersions of silica nanoparticles with different degrees of hydrophobic modification by a short chain amine. The samples show strong synergistic effects in terms of foamability and foam stability compared to solutions that contain the hydrophobic amine or unmodified silica particles only. The systems were characterized at various length scales from the nanometer to the centimeter scale. We determine the contact angle of the nanoparticles at the air water interface via x-ray reflectivity. With increasing hydrophobicity, the nanoparticles form a colloidal network around the air bubbles, whereby the apparent fractal dimension of the network shows a strong effect on foamability and foam structure.