Double Helical Conformation and Extreme Rigidity in a Rodlike Polyelectrolyte
Abstract
The ubiquitous biomacromolecule DNA has an axial rigidity persistence length of ~50 nm, driven by its elegant double helical structure. While double and multiple helix structures appear widely in nature, only rarely are these found in synthetic non-chiral macromolecules. Here we describe a double helical conformation in the densely charged aromatic polyamide poly(2,2'-disulfonyl-4,4'-benzidine terephthalamide) or PBDT. This double helix macromolecule represents one of the most rigid simple molecular structures known, exhibiting an extremely high axial persistence length (~1 micrometer). We present X-ray diffraction, NMR spectroscopy, and molecular dynamics (MD) simulations that reveal and confirm the double helical conformation. The discovery of this extreme rigidity in combination with high charge density gives insight into the self-assembly of molecular ionic composites with high mechanical modulus (~1 GPa) yet with liquid-like ion motions inside, and provides fodder for formation of new 1D-reinforced composites.
Cite
@article{arxiv.1902.00711,
title = {Double Helical Conformation and Extreme Rigidity in a Rodlike Polyelectrolyte},
author = {Ying Wang and Yadong He and Zhou Yu and Jianwei Gao and Stephanie T. Brinck and Carla Slebodnick and Gregory B. Fahs and Curt J. Zanelotti and Maruti Hegde and Robert B. Moore and Bernd Ensing and Theo J. Dingemans and Rui Qiao and Louis A. Madsen},
journal= {arXiv preprint arXiv:1902.00711},
year = {2019}
}
Comments
Accepted for publication by Nature Communications