Mechanical properties of single supramolecular polymers from correlative AFM and fluorescence microscopy
Michael Alfonsus Beuwer, Floris Knopper, Lorenzo Albertazzi, Daan van der Zwaag, Wouter G Ellenbroek, E W Meijer, Menno W J Prins and Peter Zijlstra
Polym. Chem., 2016, Accepted Manuscript
Accepted 07 Nov 2016
First published online 08 Nov 2016
We characterize the structure and mechanical properties of 1,3,5-benzenetricarboxamide (BTA) supramolecular polymers using correlative AFM and fluorescence imaging. AFM allows for nanoscale structural investigation but we found that statistical analysis is difficult because these structures are easily disrupted by the AFM tip. We therefore correlate AFM and fluorescence microscopy to couple nanoscale morphological information to far-field optical images. A fraction of the immobilized polymers is in a clustered or entangled state, which we identify based on diffraction limited fluorescence images. We find that clustered and entangled polymers exhibit a significantly longer persistence length that is broader distributed than single unentangled polymers. By comparison with numerical simulations we find significant heterogeneity in the persistence length of single unentangled polymers, which we attribute to polymer-substrate interactions and the presence of structural diversity within the polymer.