Dynamic mechanoelectrochemistry of polypyrrole membranes <i>via</i> shear-force tracking

作     者：Northcutt, Robert G. Heinemann, Christian Sundaresan, Vishnu Baba 

作者机构：Ohio State Univ Scott Lab W363 Columbus OH 43210 USA HEKA Elekt Dr Schulze GmbH Weisenstr 71 D-67466 Lambrecht Pfalz Germany Ohio State Univ Scott Lab E528 Columbus OH 43210 USA 

出 版 物：《PHYSICAL CHEMISTRY CHEMICAL PHYSICS》 (Phys. Chem. Chem. Phys.)

年 卷 期：2016年第18卷第26期

页      面：17366-17372页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 0702[理学-物理学] 

基　　金：Sundaresan's NSF EAGER Award IMR facilities grant [FG-045] HEKA Elektronik Dr Schulze GmbH German Federal Ministry of Economic Affairs and Energy [EP140424] 

主　　题：polypyrrole signal to noise ratios Materials deformation SHEAR FORCE Redox processes elastoplastic deformation oxidation reduction potential ion transport Computer algorithms 

摘      要：Mechanoelectrochemistry is the study of elastic and plastic deformation of materials during reversible reduction and oxidation processes. In this article, we introduce shear-force tracking as a method to dynamically measure mechanical (strain), chemical (ion transport), and electrical (applied redox potentials) responses of the conducting polymer polypyrrole (PPy) during redox reactions. This tracking technique uses a control algorithm to maintain a set distance between a ultramicroelectrode (UME) tip and a surface via shear-force regulation. Due to the sensitivity of shear-force signals in the near field of substrate surfaces, a significantly improved signal to noise ratio (20 : 1) is possible and allows for nanoscale measurement of redox events. Chemomechanical coupling (the ratio of ion transport to resultant extensional actuation) is calculated for PPy-based membranes of various thicknesses based on a mechanistic interpretation of charge storage in redox active conducting polymers. The measured dynamic response demonstrates that chemomechanical coupling is not a constant, as assumed in literature, but is dependent on the polymers state of charge and the direction (ingress/egress) of ion transport.