Papers by Author: Claude Chevrot

Abstract: Interpenetrating polymer networks (IPNs) have been developed for many years leading to materials with controlled properties. When an electronic conducting polymer (ECP) is incorporated into an IPN, this one becomes a conducting IPN (CIPN). The synthetic pathway ensures a non homogeneous dispersion of the ECP through the IPN thickness of the material. The system is thus similar to a layered one with the advantage that the intimate combination of the three polymers needs no adhesive interface. The last step in making the CIPN into an actuator is to ensure the ionic conductivity by incorporation of an ionic salt. The highest ionic conductivity through the IPN matrix is necessary in order to ensure the best actuation. The chosen salt is an ionic liquid, i.e. 1-ethyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImTFSI). Based on IPN architectures electrochemical actuators have been designed and actuation in open air has been characterized.

Abstract: In this work, we report the development of “one piece” electrochemical actuator fibers, presenting linear deformations, and working in open-air. The hollow fiber shaped actuators are synthesized as three components Interpenetrating Polymer Network (IPN). The electronic conducting polymer (ECP), poly(3,4-ethylenedioxythiophene) (PEDOT), is embedded in a hollow fiber shape matrix working as two ECP concentric electrodes. The host matrix which presents an IPN type architecture is composed of two poly(ethylene oxide) networks, crosslinked in the presence of each other. Strains up to 3 % and forces between 50 and 300 mN are realized in a two electrodes configuration, in open-air.

Abstract: This paper describes the elaboration and optical characterizations of electrochromic devices (ECDs) based on a semi-Interpenetrating Polymer Network architecture. These ECD exhibit contrast ration of 36% in the full visible range and are able to switch 10,000 times at low voltage between +1.2V and -1.2V with only 0.2% of electroactivity lost. By the way, these IPN-based materials present interesting properties in the NIR region.