演講快訊
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- 演講快訊
03.03
Thermoresponsive polymers under pressure
Prof. Christine M. Papadakis
摘要 :
Kinetics of mesoglobules formation and disintegration in solutions of thermoresponsive polymers after fast pressure jumps
Polymeric nanoparticles are used in many fields, e.g. for drug delivery. Poly(N-isopropylacrylamide) in aqueous solution forms nanoparticles (“mesoglobules”) above its cloud point. The coexistence line of this system in the temperature-pressure frame is an ellipse with a maximum at ~60 MPa and 35 °C. We investigate the formation and growth of mesoglobules as well as their dissolution after rapid pressure jumps across the coexistence line, both at low (below 20 MPa) and high pressures (above 100 MPa). Time-resolved small-angle neutron scattering at instrument D11 (ILL Grenoble) gives structural information on a large range of length scales and in a time range from 50 ms to ~1650 s after the jump. This way, we can identify the mechanisms and time scales for aggregation and disintegration of polymeric nanoparticles.
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Figure 1. Schematic representation of the formation and structural evolution of the mesoglobules during a pressure jump.
學經歷 :
Prof. Papadakis conducts research on experimental soft matter physics, with particular emphasis on polymers. Her research uses scattering methods with light, X-rays and neutrons to investigate polymers of complex architecture, responsive polymers, block copolymers and polymers for drug delivery. She conducts time-resolved scattering experiments during rapid changes of the environment to characterize the switching mechanisms. Neutron spectroscopy elucidates the underlying interactions with the solvent.
After studying physics at the Universities of Mainz and Grenoble, she completed her doctorate in 1996 at the University of Roskilde, Denmark. Following a postdoctoral stay (1996-98) at Risø National Laboratory, Roskilde, Denmark, Prof. Papadakis earned her postdoctoral teaching qualification at the University of Leipzig (1998-2003). She has been a professor in the TUM Department of Physics since 2003. She has been a member of proposal committees at several large-scale facilities and, was editor-in-chief at Colloid & Polymer Science, Springer Verlag, from 2015 to 2022.