10-11 December 2019
Marriott
Europe/Berlin timezone

Structural Properties of Micelles formed by Telechelic Pentablock Quaterpolymers with pH-responsive Midblocks and Thermo-responsive End Blocks in Aqueous Solution

10 Dec 2019, 14:05
25m
Marriott Conference room - Munich (Marriott)

Marriott Conference room - Munich

Marriott

Berliner Str. 93 80805 München Germany
300
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Talk Soft Matter Soft Matter

Speaker

Mr Florian Jung (Technische Universität München)

Description

Stimuli-responsive polymers are of interest for applications in drug delivery or tissue engineering. Telechelic block copolymers, where a pH-responsive midblock is end-capped by thermo-responsive end blocks, have great potential due to their ability to form highly tunable micelles or hydrogels.
In the present work, micelles formed by the telechelic pentablock quaterpolymer P(nBuMA$_8$-co-TEGMA$_8$)-b-PDMAEMA$_{50}$-b-PEG$_{46}$-b-PDMAEMA$_{50}$-b-P(nBuMA$_8$-co-TEGMA$_8$) in dilute aqueous solution are investigated as a function of temperature and pH. The endblocks are statistical copolymers of the thermo-responsive TEGMA (triethylene glycol methyl ether methacrylate) and the hydrophobic nBuMA (n-butyl methacrylate). The intermediate PDMAEMA poly(2-(dimethylamino)ethyl methacrylate) block is a weak cationic polyelectrolyte. The hydrophilic poly(ethylene glycol) (PEG) block ensures water-solubility. Using small-angle neutron scattering (SANS) at KWS-1, FRM II, we found that the micelles have a spherical core and a strongly swollen corona. Their aggregation number and size depend sensitively on the pH and temperature. At low temperatures, some polymers form dangling ends, especially at low pH values. With increasing temperature, dangling ends transform into loops at high pH values, while they are stabilized at low pH values. In summary, the micelles show complex responsive behavior in dependence on temperature and the pH value.

Primary author

Mr Florian Jung (Technische Universität München)

Co-authors

Ms Panayiota A. Panteli (Department of Chemistry, University of Cyprus) Ms Chia-Hsin Ko (E13, Physik-Department, Technische Universität München.) Ms Jia-Jhen Kang (Technical University of Munich) Dr Lester Barnsley (Jülich Centre for Neutron Science) Prof. Constantinos Tsitsilianis (Department of Chemical Engineering, University of Patras) Prof. Costas S. Patrickios (Department of Chemistry, University of Cyprus) Prof. Christine Papadakis (Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie)

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