Speaker
Tobias Widmann
(TUM, Physik Department, E 13)
Description
Strong volume shifts of polymer thin films due to small modifications of an external stimulus like temperature are desired for a number of applications such as thermoresponsive nanoswitches or drug delivery in medicine. In this context the polymer which received most attention so far is poly(N-isopropylacrylamide), PNIPAM. The volume shift arises due to the collapse transition of the polymer at a lower critical solution temperature (LCST) which manifests in a swelling or deswelling of the polymer with water from its surroundings. To further our understanding of the kinetics of water uptake, release and exchange and the induced changes of the polymer properties, microgel thin films from a PNIPAM homopolymer with varying amounts of N,N'-Methylenebisacrylamide cross-linkers are prepared. In-situ neutron reflectometry in time of flight (TOF) mode is used to investigate the uptake and exchange kinetics of H2O with D2O and vice-versa for these films at temperatures below the LCST of PNIPAM.
Primary author
Tobias Widmann
(TUM, Physik Department, E 13)
Co-authors
Dr
Jean-Francois Moulin
(HZG)
Kun Wang
(Technische Universität München Fakultät für Physik Lehrstuhl für Funktionelle Materialien)
Mr
Lucas Kreuzer
(TU München, Physik Department, E13)
Nuri Hohn
(TU München, Physik-Department, LS Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching)
Prof.
Peter Müller-Buschbaum
(TU München, Physik-Department, LS Funktionelle Materialien)
Thomas Hellweg
(Bielefeld University, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld)
Yvonne Hertle
(Bielefeld University, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld)
