Regensburg 2019 – wissenschaftliches Programm
CPP 25.22: Poster
Dienstag, 2. April 2019, 14:00–16:00, Poster B1
Investigation of Non-Equilibrium Actuation Dynamics of Microgel Disks — •Niklas O. Junker1, Jonas Staudenmeir1, Marcel van Dongen2, Sebastian Meyer1, Dmitry N. Chigrin1,2, Ahmed Mourran2, Martin Möller2, and Gero von Plessen1 — 1Institute of Physics (IA), RWTH Aachen, Germany — 2DWI - Leibniz Institute for Interactive Materials, Aachen, Germany
Microgels are cross-linked polymer networks of micrometer or submicrometer dimensions. Suspended in a solvent, they can undergo large and fast volume changes in response to variations of external parameters (temperature, pH, etc.). In the present work, microgel disks made of poly(N-isopropylacrylamide) (PNIPAm) homogeneously loaded with gold nanorods have been investigated in water. Non-equilibrium actuation dynamics triggered by rapid heating and cooling is studied. The microgels are found to swell with decreasing temperature much faster than they shrink with increasing temperature. This behavior is systematically studied for different heating rates (up to 150°C/min for conventional heating and up to approximately 1°C/ms for photothermal heating, in which the gold nanorods are used as fast and efficient photoabsorbers and local heaters). Experimental and simulation results are compared for both cases.