Regensburg 2022 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 35: Nanomaterials: Structure & Properties

MM 35.6: Vortrag

Donnerstag, 8. September 2022, 17:15–17:30, H46

Electrochemical actuation and tunable stiffness of hierarchical nanoporous gold via surface modification — •Olga Matts and Nadiia Mameka — Helmholtz-Zentrum Hereon, Geesthacht, Germany

Recently developed dealloying strategies towards nanoporous metals with structural hierarchy [1] open up new opportunities for functional behavior of this class of materials. The larger pores at the higher hierarchical level (characterized by diameters around 200 nm) of the hierarchical nanoporous metals (hc np) can promote fast mass exchange, while nanopores at the lower hierarchy level (below 30 nm) provide a large surface area. To explore the notion we employ electroactive self-assembled monolayers and conductive polymer polypyrrole for surface functionalization of hc np Au and np Au with unimodal pore size. Actuation and Young*s modulus behavior of the hybrid materials were then analyzed in situ in a dynamical mechanical analyzer and dilatometer upon potential cycling in aqueous electrolytes. We revealed pronounced variations in the macroscopic length change as well as elastic modulus in response to the voltage-induced redox reactions of the organic films at the np electrodes. In the contribution, we discuss the origin of the observations and compare the functional performance of both types of the hybrids based on np Au.

[1] Shi et al., Science 371, 1026*1033 (2021).