posted on 2024-07-10, 20:06authored byEmmanouil Archontakis, Shikha Dhiman, Miao Zhang, Marle E. J. Vleugels, E. W. Meijer, Anja R. A. Palmans, Peter Zijlstra, Lorenzo Albertazzi
The dynamic properties of supramolecular polymers enable
new functionality
beyond the limitations of conventional polymers. The mechanism of
the monomer exchange between different supramolecular polymers is
proposed to be closely associated with local disordered domains within
the supramolecular polymers. However, a direct detection of such heterogeneity
has never been experimentally probed. Here, we present the direct
visualization of the local disordered domains in the backbone of supramolecular
polymers by a super-resolution microscopy technique: Nile Red-based
spectrally resolved point accumulation for imaging in nanoscale topography
(NR-sPAINT). We investigate the local disordered domains in trisamide-based
supramolecular polymers comprising a (co)assembly of benzene-1,3,5-tricarboxamide
(BTA) and a variant with one of the amide bonds inverted (iBTA). The
NR-sPAINT allows us to simultaneously map the spatial distribution
and polarity of the local disordered domains along the polymers with
a spatial precision down to ∼20 nm. Quantitative autocorrelation
and cross-correlation analysis show subtle differences in the spatial
distribution of the disordered domains between polymers composed of
different variants of BTA monomers. Further, statistical analysis
unraveled high heterogeneity in monomer packing at both intra- and
interpolymer levels. The results reported here demonstrate the necessity
of investigating the structures in soft materials at nanoscale to
fully understand their intricacy.