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Title: Tuning of the elastic modulus of a soft polythiophene through molecular doping
Molecular doping of a polythiophene with oligoethylene glycol side chains is found to strongly modulate not only the electrical but also the mechanical properties of the polymer. An oxidation level of up to 18% results in an electrical conductivity of more than 52 S cm −1 and at the same time significantly enhances the elastic modulus from 8 to more than 200 MPa and toughness from 0.5 to 5.1 MJ m −3 . These changes arise because molecular doping strongly influences the glass transition temperature T g and the degree of π-stacking of the polymer, as indicated by both X-ray diffraction and molecular dynamics simulations. Surprisingly, a comparison of doped materials containing mono- or dianions reveals that – for a comparable oxidation level – the presence of multivalent counterions has little effect on the stiffness. Evidently, molecular doping is a powerful tool that can be used for the design of mechanically robust conducting materials, which may find use within the field of flexible and stretchable electronics.  more » « less
Award ID(s):
1921854
NSF-PAR ID:
10302332
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Date Published:
Journal Name:
Materials Horizons
ISSN:
2051-6347
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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