Counter-ion and humidity effects on electromechanical properties of Nafion (R)/Pt composites

Author(s)

Saccardo, Matheus Colovati ^[1] ; Zuquello, Ariel Gustavo ^[1] ; Tozzi, Kaique Afonso ^[1] ; Goncalves, Roger ^[1] ; Hirano, Laos Alexandre ^[2] ; Scuracchio, Carlos Henrique ^[1]

Affiliation

^[1] Fed Univ Sao Carlos UFSCar, Mat Engn, Sao Carlos, SP - Brazil

^[2] Fed Univ Alfenas UniFAl, Inst Sci & Technol, Pocos De Caldas, MG - Brazil

• Document type: Journal article
• Source: Materials Chemistry and Physics; v. 244, APR 1 2020.
• Web of Science Citations: 1

Abstract

Ionomeric polymer/metal composites (IPMCs) are smart materials that deform in response to electrical stimuli and vice versa. Its electromechanical performance depends on several factors, such as the electrical stimulus, environment humidity, counterions, and the number of actuation cycles. For this reason, in this paper, the electromechanical response of Pt-Nafion (R) IPMC samples was evaluated using several counterion types (H+, Li+, Na+, K+ and Ionic Liquid) and relative humidities. Results showed that the electromechanical behaviour of the IPMC was strongly influenced by the counterion type and polymer matrix hydration level (RH). Blocking force, Electric Charge Storage and the Coulombic Efficiency of the devices increased with the reduction of counterion ionic radius and increase of the hydration level of the polymeric matrix. An atypical current response, associated with water electrolysis, was observed for samples incorporated with H+ counterion. The mechanical performance decreased with the number of cycles, showing a limited life cycle for the device. SEM images presented that Pt surface cracks density increases after several actuations, harming the performance of the IPMC. As the main conclusion, this work shows that the hydration level and the counterion type exert a great influence on IPMC electromechanical properties, being the hydration level more prevailing than counterion. (AU)

• FAPESP's process: 18/10843-9 - Study of deformation behavior of artificial muscles based on electroactive polymers: performance enhancement proposal
• Grantee: Matheus Colovati Saccardo
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 18/09761-8 - Study and development of ionic polymer/metal composites for application in actuators and sensors aiming low cost and high performance
• Grantee: Roger Gonçalves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/07001-6 - Study and characterization of ionic conductive polymers used as artificial muscles: proposals for performance improvement
• Grantee: Carlos Henrique Scuracchio
• Support Opportunities: Regular Research Grants