Soft and flexible Interpenetrating Polymer Networks hosting electroreflective poly(3,4-ethylenedioxythiophene)

• Published in: Solar energy materials and solar cells Vol. 127; pp. 33 - 42
• Main Authors: GOUJON, Laurent J, AUBERT, Pierre-Henri, SAUQUES, Laurent, VIDAL, Frédéric, TEYSSIE, Dominique, CHEVROT, Claude
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.08.2014
• Subjects: Applied sciences; Breaking; Chemical Sciences; Devices; Elongation; Energy; Exact sciences and technology; Interpenetrating networks; Natural energy; Networks; Optical properties; Polymers; Switching theory; Electrical switching; Polyethylene; Nitrile; Poly(3,4-ethylenedioxythiophene); Ionic conductivity; Polymerization; Mechanical properties; Parallel; Optimization; Interpenetrating polymer network; Ionic liquid; Ethylene oxide polymer; Electroreflective device; Imide; Thiophene derivative polymer; Modulation; Optical properties; Poly(ethylene oxide); Infrared spectrum; Rubber; Reflectance; Nitrile butadiene rubber
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2014.03.036

In this paper, we designed a flexible electroreflective device (ERD) with tunable optical properties in the near and mid infrared spectra. The ERD is made of a poly(3,4-ethylenedioxythiophene) (PEDOT) layer interpenetrated in a soft and flexible nitrile butadiene rubber (NBR)/polyethylene oxide (PEO) interpenetrating polymer network (IPN). The composition, structure and infrared properties of the semi-IPN were optimized according to the polymerization time of the EDOT monomer within the IPN. After the addition of an ionic liquid (IL), namely N-ethylmethylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI), assuming the ionic conductivity of the system, the device exhibits middle infrared and tunable optical properties between 2 mu m and 20 mu m upon electrical switching between -1.5 V and + 1.5 V. The modulation of the reflectivity in bands II (3-5 mu m) and III (8-12 mu m) regions is 26% and 41% respectively. Due to the presence of the soft NBR network, both IPN and ERD reveal improved mechanical properties compare to the single network and the ERD-only based on PEO. For instance, ERDs made with PEO/PEDOT semi-IPN possesses an elongation at break below 10%, for a stress at break lower than 1.4 MPa, while ERDs containing NBR show elongations at break from 45% to 15% for stresses at break from 3 to 8 MPa, depending on the amount of incorporated PEDOT. In parallel, the NBR/PEO/ PEDOT devices showed robust and flexible behavior.