Mar 20 – 23, 2023
Campus Garching
Europe/Berlin timezone

Effect of pressure on the micellar structure of PMMA-b-PNIPAM in aqueous solution

Mar 20, 2023, 4:00 PM
Yards 4 - 6 (Fakultät für Maschinenwesen)

Yards 4 - 6

Fakultät für Maschinenwesen

Board: MO-007
Poster Soft Condensed Matter Poster Session MONDAY


Pablo Alvarez Herrera (Technical University of Munich)


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 of PNIPAM (Tcp) [1]. Previously, it was found that pressure strongly affects the dehydration extent of PNIPAM homopolymers in aqueous solution [2].
Here, we present 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, we find that the micellar shell strongly dehydrates above Tcp at atmospheric pressure. In contrast, at 75 MPa, it remains hydrated, and the micelles form highly correlated aggregates. We also characterized the micellar structure in a pressure-resolved experiment at 31.8 °C. We find that, after crossing the co-existence line, the micellar shell appreciably shrinks, despite it remains partially hydrated. Thus, pressure is a tool to modify the micellar structure and the aggregation behavior of the micelles.
[1] C.H. Ko, C.M. Papadakis et al., Macromolecules. 2021, 54, 384.
[2] B.-J. Niebuur, C. M. Papadakis et al., ACS Macro Lett. 2017, 6, 1180.

Primary author

Pablo Alvarez Herrera (Technical University of Munich)


Prof. André Laschewsky (Universität Potsdam, Institut für Chemie,) Christine Papadakis (Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie) Mrs Cristiane Henschel (Universität Potsdam, Institut für Chemie) Mrs Geethu P. Meledam (Technical university of Munich) Dr Leonardo Chiappisi (Institut Laue-Langevin, Grenoble, France)

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