Time-Dependent Flow in Arrested States (A06)

• Fachliche Zuordnung: Experimentelle Physik der kondensierten Materie
• Förderung: Förderung von 2005 bis 2013
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 5485412

This project concerns the combined theoretical and experimental investigation of highly concentrated colloidal liquids and dynamically arrested states under time-dependent shear. In the second funding period (our first funding period) a new and comprehensive theoretical framework was developed to describe concentrated liquids as well as colloidal glasses and gels subject to an arbitrary flow history. Furthermore, a shear cell was designed, constructed and tested which allows us to study colloidal suspensions under flow with the confocal microscope and light scattering. This theoretical approach and experimental set-up was already applied to concentrated colloidal suspensions and yielded consistent results. We now want to exploit this new methodology and apparatus to investigate in detail the time-dependent response of dense fluids and arrested states, bridging the gap between the microscopic and macroscopic levels of description. Particular emphasis will be given to, (i) switch-on shear flow, (ii) switch-off shear flow, (iii) large amplitude oscillatory shearing. The competition of timescales and dependence on flow history is expected to lead to novel features in both the rheological response and microscopic dynamics.

• DFG-Verfahren: Transregios
• Teilprojekt zu: TRR 6: Physik von kolloidalen Dispersionen in äußeren Feldern
• Antragstellende Institution: Heinrich-Heine-Universität Düsseldorf
• Mitantragstellende Institution: Universität Konstanz
• Teilprojektleiter: Professor Joseph M. Brader, Ph.D., bis 6/2010; Professor Dr. Stefan U. Egelhaaf (†); Professor Dr. Matthias Fuchs