Exploring the Loading Capacity of Generation Six to Eight Dendronized Polymers in Aqueous Solution.
Aspects of size, structural (im)perfection, inner density, and guest molecule loading capacity of dendronized polymers (DPs) of high generation (6≤g≤8) in aqueous solution are studied using electron paramagnetic resonance spectroscopy on amphiphilic, spin-labeled guest molecules. The results show that the interior of the charged DPs is strongly polar, especially in comparison to their lower generation (1-4) analogues. This is a direct sign that large amounts of water penetrate the DP surface, reflecting the structural (im)perfections of these high-generation DPs and much lower segmental densities than theoretically achievable. Images obtained with atomic force microscopy reveal that the high-generation DPs do not aggregate and give further insights into the structural imperfections. Electron paramagnetic resonance spectroscopic data further show that despite their structural imperfections, these DPs can bind and release large numbers of amphiphilic molecules. It is concluded that attention should be paid to their synthesis, for which a protocol needs to be developed that avoids the relatively large amount of defects generated in the direct conversion of a generation g=4 DP to a generation g=6 DP, which had to be used here.
Martin-Luther-Universität Halle-Wittenberg, Institut für Chemie, Von-Danckelmann-Platz 4, 06120, Halle, Germany.|Ruđer Bošković Institute, Division of Physical Chemistry, Laboratory for Magnetic Resonance, Bijenička 54, 10000, Zagreb, Croatia.
Nadica
N
Maltar-Strmečki
ETH Zürich, Department of Materials, Laboratory of Polymer Chemistry, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland.|University of Bern, Department of Chemistry and Biochemistry, Freiestrasse 3, 3012, Bern, Switzerland.
Hao
H
Yu
ETH Zürich, Department of Materials, Laboratory of Polymer Chemistry, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland.
Daniel
D
Messmer
ETH Zürich, Department of Materials, Laboratory of Polymer Chemistry, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland.|Lund University, Centre of Analysis and Synthesis, P.O. Box 124, 22100, Lund, Sweden.
Baozhong
http://orcid.org/0000-0002-7308-1572
B
Zhang
ETH Zürich, Department of Materials, Laboratory of Polymer Chemistry, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland. dieter.schluter@mat.ethz.ch.
A Dieter
AD
Schlüter
Martin-Luther-Universität Halle-Wittenberg, Institut für Chemie, Von-Danckelmann-Platz 4, 06120, Halle, Germany. dariush.hinderberger@chemie.uni-halle.de.
Dariush
http://orcid.org/0000-0002-6066-7099
D
Hinderberger
ESR/EPR spectroscopy; dendronized polymers; host-guest interactions; macromolecules; spin labels