SKM 2021 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 8: Poster Session III
CPP 8.31: Poster
Wednesday, September 29, 2021, 17:30–19:30, P
Effect of pressure on the micellar structures of PMMA-b-PNIPAM in aqueous solution — •Pablo A. Álvarez Herrera1, Geethu P. Meledam1, Chia-Hsin Ko1, Bart-Jan Niebuur1, Shu-Hsien Huang1, Leonardo Chiappisi2, Cristiane Henschel3, André Laschewsky3, Alfons Schulte4, and Christine M. Papadakis1 — 1TU München, Physik-Department, Garching, Germany — 2Institut Laue-Langevin, Grenoble, France — 3Universität Potsdam, Institut für Chemie, Potsdam-Golm, Germany — 4University of Central Florida, Orlando, USA
Amphiphilic diblock copolymers feature self-assembly behavior in aqueous solution. In particular, poly(methyl methacrylate)-b-poly(N-isopropylacrylamide) (PMMA-b-PNIPAM) forms core-shell micelles upon heating above the cloud point (TCP). In aqueous solutions of PNIPAM homopolymers, it was previously found that the dehydration behavior is strongly altered by pressure [1]. We study the effect of pressure on the micellar structure of PMMA-b-PNIPAM in aqueous solution by small-angle neutron scattering (SANS). In temperature-resolved experiments at 0.1 and 75 MPa, we find that the micelles dehydrate and collapse above TCP at low pressure, while the PNIPAM shells remain hydrated, and the micelles form large clusters at higher pressure.
1.B.-J. Niebuur, C. M. Papadakis et al., ACS Macro Lett. 2017, 6, 1180 and Macromolecules 2019, 52, 1942.