Regensburg 2022 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster 2

CPP 17.18: Poster

Dienstag, 6. September 2022, 11:00–13:00, P2

Core-shell microgels synthesized in continuous flow: Deep insight into shell growth by temperature-dependent FTIR spectrocopy — •Pascal Fandrich¹, Marco Annegarn¹, Lars Wiehemeier¹, Ina Ehring¹, Tilman Kottke², and Thomas Hellweg¹ — ¹Physical and Biophysical Chemistry, Bielefeld University, 33615 Bielefeld, Germany — ²Biophysical Chemistry and Diagnostics, Bielefeld University, 33615 Bielefeld, Germany

While core-shell microgels have been intensively studied in their fully synthesized state, the formation mechanism of the shell growth has not been completely understood. Such insight is decisive for a customization of microgel properties for applications. In a novel approach, we synthesized microgels based on a N-isopropylmethacrylamide (NiPMAM) core and a N-n-propylacrylamide (NnPAM) shell in a continuous flow reactor. The shell growth is studied depending on the solution's time of residence inside the reactor. PCS experiments reveal a significant decrease of the volume phase transition temperatures of the core and the shell respectively, with increasing residence time. At early stages, a decreased swelling capacity is found before a discrete NnPAM shell is formed. Temperature-dependent FTIR spectroscopy shows that the decreased swelling capacity originates from a pronounced interpenetrated network between NnPAM and NiPMAM. AFM images resolve a raspberry-like structure after 3 min, pointing to an aggregation of NnPAM domains before the distinct shell forms.