Influence of water on electrical and mechanical properties of self-assembled and self-healing PEM films

Author(s)

Gaal, Gabriel ^[1] ; Jimenez, Mawin J. M. ^[1] ; Alvarez, Fernando ^[1] ; Rodrigues, Varlei ^[1] ; Riul Jr, Antonio

Affiliation

^[1] Univ Estadual Campinas, Dept Fis Aplicada, Campinas - Brazil

• Document type: Journal article
• Source: Progress in Organic Coatings; v. 150, JAN 2021.
• Web of Science Citations: 0

Abstract

Self-healing coatings as thin films have been widely exploited in the last decade due to the conformational ability to adhere practically at any surface, bringing multiple regenerations in damaged areas. Poly(ethylene imine) (PEI) and poly(acrylic acid) (PAA) are the most used polyelectrolytes to grow self-healing layer-by-layer films; however, few studies have been dedicated to evaluate the role of water on the electrical and mechanical properties of the films. Multilayered (PEI/PAA) structures were easily self-assembled on various substrates, allowing homogeneous and semi-transparent coverages. We associate the exponential and linear growth regimes of (PEI/PAA) with changes in the electrical characteristics acquired after each step of the film formation. We demonstrated the central role of trapped water on the space charge accumulation at polymer/electrode interface, due to the presence of negative differential resistance regions, and the transition of the charge transport to a space charge regime after a critical potential. We have also investigated changes in the mechanical properties, showing the influence of trapped water in the film elastic modulus, wear resistance, and resistance to plastic deformation. (AU)

• FAPESP's process: 19/18460-4 - Synthesis, thermo-mechanical and tribological properties of advanced multicomponent materials of high entropy
• Grantee: Fernando Alvarez
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/19862-3 - Study of nanostructured conducting and self-healing films for flexible electronics application
• Grantee: Gabriel Gaál
• Support Opportunities: Scholarships in Brazil - Doctorate