ma5b00604_si_001.pdf (1.97 MB)
The Coil-to-Globule Transition of Single-Chain Polymeric Nanoparticles with a Chiral Internal Secondary Structure
journal contribution
posted on 2015-06-23, 00:00 authored by Gijs M. ter Huurne, Martijn
A. J. Gillissen, Anja R. A. Palmans, Ilja K. Voets, E. W. MeijerThe intramolecular folding of chiral
single polymeric chains into single-chain polymeric nanoparticles
(SCPNs) via π-stacking was investigated. To this end, hydrophilic
polymers grafted with structuring, chiral 3,3′-bis(acylamino)-2,2′-bipyridine-substituted
benzene-1,3,5-tricarboxamides (BiPy-BTAs) units were prepared via
ring-opening metathesis polymerization (ROMP). A combination of spectroscopic
and scattering techniques was employed to obtain a better understanding
of the folding behavior and the chiral internal structure of these
systems. Circular dichroism spectroscopy showed that the folding of
the polymer is highly dependent on the solvent quality and temperature.
The folding process in water was fine-tuned via the addition of a
good cosolvent (tetrahydrofuran), resulting in an optimal balance
between the conformational freedom of the polymer’s backbone
and the stability of the π-stacked units. Small-angle X-ray
scattering (SAXS) experiments showed that the shape of the SCPNs is
controlled by the formation of a chiral internal secondary structure.