Warning: We observe an increase of emails from fake travel portals like . "travelhosting.co.uk". We never send links to such portals so be vigilant!

10–11 Dec 2019
Marriott
Europe/Berlin timezone

The Structural and Thermal Behavior of the Thermoresponsive Polymer Poly(N-isopropylmethacrylamide) in Aqueous Solution

11 Dec 2019, 13:30
3h
Marriott Conference room - Munich (Marriott)

Marriott Conference room - Munich

Marriott

Berliner Str. 93 80805 München Germany
300
Show room on map
Board: 38
Poster Soft Matter Poster session

Speaker

Chia-Hsin Ko (E13, Physik-Department, Technische Universität München.)

Description

Compared to the well-investigated poly(N-isopropylacrylamide) (PNIPAM), Poly(N-isopropylmethacrylamide) (PNIPMAM) has a higher phase transition temperature (43 °C instead of 32 °C). This may be due to the presence of the additional methyl groups on the vinyl backbone, which lead to steric hindrance and weaken the intramolecular interactions. To understand how these effects influence the thermal and structural behavior of PNIPMAM aqueous solutions, we investigate the phase behavior of PNIPMAM in D$_{2}$O using turbidimetry, differential scanning calorimetry, Raman spectroscopy, small-angle and very small-angle neutron scattering (at KWS-1 and KWS-3 at MLZ). The PNIPMAM solutions undergo first macroscopic phase transition, but the PNIPMAM chains only dehydrate 2~3 °C above T$_{CP}$. The methyl groups in PNIPMAM lead to loosely packed large-scale inhomogeneities, and physical crosslinks already in the one-phase state. Besides, the local chain conformation of PNIPMAM is more compact than the one of PNIPAM, which is due to enhanced attractive intermolecular interactions originating from the hydrophobic moieties. In the two-phase state, PNIPMAM features larger and more hydrated mesoglobules than PNIPAM. This is due to the steric hindrance caused by the methyl groups, which weaken the intrapolymer interactions. We conclude that the methyl groups in PNIPMAM chains have a significant impact on the hydration behavior and the structural behavior around the phase transition.

Primary author

Chia-Hsin Ko (E13, Physik-Department, Technische Universität München.)

Co-authors

Ms Kora-Lee Claude (Technical University of Munich) Dr Dirk Schanzenbach (University of Potsdam) Bart-Jan Niebuur (TU München, Physik weicher Materie) Florian Jung (Technische Universität München) Jia-Jhen Kang (Technical University of Munich) Henrich Frielinghaus (JCNS) Lester Barnsley (Jülich Centre for Neutron Science) Vitaliy Pipich Baohu Wu (JCNS-MLZ, FZ Juelich) Alfons Schulte (University of Central Florida) André Laschewsky (University of Potsdam, Applied Polymer Chemistry Group, Potsdam-Golm) Christine M. Papadakis (4Technical University of Munich, Soft Matter Physics Group, Garching)

Presentation materials

There are no materials yet.