resumo
The evolving usefulness of organic conducting polymers, of metallic or semi-conducting type, is primarily dependent on their mechanisms of electrical conduction and degradation. Understanding these mechanisms is crucial for improving the efficiency and lifetime of technologies derived from this class of polymers. There is demand for a model that provides a vivid and more precise evaluation of the electrical conduction mechanism in these polymers - especially when they act as hosts to guest species, such as acid dopant ions and nanoparticles. If, for example, the motional behavior of a host-guest organic conducting polymer structure, as related to dynamic stability, is either asynchronous or synchronous, is this reflected in the mechanism of electrical conduction and does it account for the pace of material's degradation? Here, we demonstrate that the answer is affirmative: asynchronous structural motions arising due to loosely bound or free guest species within the host polymer lead to anomalous electrical conduction mechanisms, increased fragility and short lifetime, at odds with the synchronous behavior.
palavras-chave
GLASS-TRANSITION; METALLIC CONDUCTIVITY; HOPPING CONDUCTIVITY; TRANSPORT-PROPERTIES; DISORDERED-SYSTEMS; LOW-TEMPERATURES; GOLD SURFACES; SULFUR 2P; FILMS; POLY(3,4-ETHYLENEDIOXYTHIOPHENE)
categoria
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
autores
Chimamkpam, EFC; Schweizer, T; Hauert, R; Schilling, A; Ferreira, JMF
nossos autores
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)Projectos
Development of microelectromechanical systems by gelcasting - GELMEMS (PTDC/CTM/099489/2008)
agradecimentos
We gratefully acknowledge the financial support of the European Commission, the Portuguese Foundation for Science and Technology (FCT PTDC/CTM/099489/2008) and the Centre for Research in Ceramics and Composite Materials, CICECO. We thank Dr. Andreas Engel and Stefan Siegrist at the University of Zurich for providing support during electrical transport measurements. Technical help for cryo-SEM analyses by staff members of the Electron Microscopy Centre ETH Zurich, EMEZ is happily acknowledged. EFCC thanks the University of Zurich and the Swiss National Science Foundation (SNSF PP002-114711/1) for their support.