Nanoporous gold-polypyrrole hybrid electrochemical actuators with tunable elasticity

Publikationstyp
Journal Article
Date Issued
2021-06-15
Sprache
English
Author(s)
Li, Jie  
Markmann, Jürgen 
Weissmüller, Jörg  
Mameka, Nadiia  
Institut
Werkstoffphysik und -technologie M-22  
TORE-URI
http://hdl.handle.net/11420/9640
Journal
Acta materialia  
Volume
212
Article Number
116852
Citation
Acta Materialia 212: 116852 (2021-06-15)
Publisher DOI
10.1016/j.actamat.2021.116852
Scopus ID
2-s2.0-85105693943
This study explores the effective elastic response of hybrid electrochemical actuators based on nanoporous gold – decorated with a thin film of an electrosynthesized polypyrrole – during charging in an aqueous electrolyte. We found a new and yet unrevealed phenomenon in the hybrids – a reversible change of the material's elasticity with alternating stiffening and softening behavior. Remarkably, the stiffness variations are larger and of opposite sign as compared to a non-coated nanoporous gold. The amplitude of the elastic modulus variation increases with the thickness of the polypyrrole layer, pointing to a dominant role of processes in the polymer bulk upon its doping or undoping. We propose that the reversible stiffness of the hybrid material is governed by the competition between the increased intermolecular bonding as consequence of interactions between the charged chains and dopant anions in the polymer and its plasticization due to solvent intake.
Subjects
Actuation
Dealloying
Dynamic mechanical analysis
Nanoporous
Polypyrrole