ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
Films of conducting polymers, when used as electrodes in an electrolytic solution,oxidize and reduce under flow of anodic or cathodic currents, respectively. Theelectrochemical reactions induce conformational movements of the chains, generation ordestruction of free volume and interchange of ions and solvent with the electrolyte giving agel that reacts, swells or shrinks. Electric pulses acting on reactive gels constituted bypolymers, solvent and ions are the closest artificial material to those that constitute actuatingbiological organs. The electrochemical reaction is kinetically controlled by the conformationalmovements or by the counterions diffusion through the gel: it works under electrochemicalquasi-equilibrium and defines, at any intermediate oxidation state, equilibrium potentials. Anyvariable (mechanical, chemical, optical, magnetic..) acting on the equilibrium will inducechanges on the working potential of any device, driven by a constant current, based on thisreaction: actuating-sensing devices based on the electrochemical properties are expected.The activation energy of the reaction can be obtained from the oxidation of metal coatedelectrodes. This energy includes two terms: the constant chemical activation energy and theconformational energy related to the packed structure of the polymeric conformations. Thisconformational energy is the basic magnitude for both actuating and sensing properties,opening the way for their quantification. Information can be stored in continuousconformational energetic levels being read by anodic oxidation
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.61.112.pdf
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