Berlin 2012 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 5: Soft Matter I

DY 5.8: Talk

Monday, March 26, 2012, 16:45–17:00, MA 004

Dynamic phase behaviour of soft colloids — •Sudipta Gupta, Stellbrink Joerg, and Richter Dieter — JCNS1/ICS1, Forschungszentrum Juelich, 52425 Germany

Soft colloids, e.g. polymer-coated silica particles, block copolymer micelles, star polymers etc., are hybrids between (linear) polymer chains and (hard sphere) colloids. Due to this hybrid nature, soft colloids macroscopically show interesting (phase) behaviour resulting from its unique microscopic structure. We introduce kinetically frozen diblock copolymer micelles as an "easy-to-establish" and "tuneable" model system for soft colloids. The micellar architecture was tuned from the star-like to the crew-cut regime by varying the block-ratio. The micellar structure was successfully determined using SANS. At the same time, we are studying the flow properties both at semi-dilute and at concentrated regime for this different block ratio, using rheology. By constructing a dynamic phase diagram we can conclude that the macroscopic flow properties do strongly depend on the microscopic structure determined by SANS. Thereby we investigate the basic principles of the so-called structure-property-relationship (SPR) that finally enables tailoring material properties for technical applications. The change in block ratio significantly affects the phase behaviour of this particular class of soft colloids. A more detailed investigation of this phase behaviour is still under progress.