Impact of Local Stiffness on Entropy Driven Microscopic Dynamics of Polythiophene.

Autor: Gupta S; Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA. g.sudipta26@gmail.com., Chatterjee S; Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA., Zolnierczuk P; Jülich Centre for Neutron science (JCNS) and outstation at SNS, POB 2008, 1 Bethel Valley Road, TN, 37831, Oak Ridge, USA., Nesterov EE; Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA. een@niu.edu.; Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA. een@niu.edu., Schneider GJ; Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA. gjschneider@lsu.edu.; Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA. gjschneider@lsu.edu.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2020 Jun 19; Vol. 10 (1), pp. 9966. Date of Electronic Publication: 2020 Jun 19.
DOI: 10.1038/s41598-020-66354-6
Abstrakt: We exploited the high temporal and spatial resolution of neutron spin echo spectroscopy to investigate the large-scale dynamics of semiflexible conjugated polymer chains in solutions. We used a generalized approach of the well-established Zimm model of flexible polymers to describe the relaxation mode spectra of locally stiff polythiophene chains. The Zimm mode analysis confirms the existence of beads with a finite length that corresponds to a reduced number of segmental modes in semiflexible chains. Irrespective of the temperature and the molecular weight of the conjugated polymer, we witness a universal behavior of the local chain stiffness and invariability of the bead length. Our experimental findings indicate possibly minor role of the change in π-electron conjugation length (and therefore conjugated backbone planar to non-planar conformational transition) in the observed thermochromic behavior of polythiophene but instead point on the major role of chain dynamics in this phenomenon. We also obtained the first experimental evidence of an existence of a single-chain glass state in conjugated polymers.
Databáze: MEDLINE
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