Dresden 2006 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 7: SYMPOSIUM Disperse Polymer Systems I

CPP 7.1: Invited Talk

Tuesday, March 28, 2006, 09:30–10:00, ZEU 160

Structure and interfacial rheology of aggregated two dimensional suspensions — •Jan Vermant¹, Sven Reynaert¹, Madivala Basavaraj¹, Moldenaers Paula¹, and Franssaer Jan² — ¹Department of Chemical Engineering, K.U. Leuven, Belgium — ²Department of Metallurgy and Materials Science, K.U. Leuven, Belgium

Tailoring the structure and rheological properties of particle-laden interfaces is of importance in a number of practical applications such as the stabilization of emulsions, polymer blends and foams. In the present work, different methods are compared to generate weakly aggregated two-dimensional suspensions with controlled interactions. Adequate combinations of electrolyte and surfactant destabilized particulate monolayers, both at the water-oil and water-air interface. The structural and kinetic aspects of the induced structures are compared to the underlying changes in the interparticle interactions, and the conditions under which reproducible results could be induced are reported and discussed. ALso effects of particle shape are explored. Secondly, a magnetic needle interfacial rheometer is used to characterize the rheological behaviour of the particle monolayer. Preliminary results show the presence of a two-dimensional yield stress and control over the surface rheology much like for the three dimensional weakly aggregated suspensions.