This paper describes ambipolar polymers made of penta­(N-alkyl carbazole)-corannulene extended viologen for use as an electrochromic supercapacitor. Electrochromic supercapacitors with visible energy storage levels and high charge/discharge rates have been used to power wearable and portable intelligent electronics. Redox-active π-conjugated polymers have received significant attention because they can change color and store energy through a faradaic reaction during the doping/dedoping process. However, conjugated ambipolar polymers used as electrochromic supercapacitors generally display color at both neutral and doped states because of the extensive conjugation of the donor and acceptor units. The alkyl chain as a nonconjugated linker bridged the donor and acceptor units to help retain the electrochromic behaviors of the individual unit and pursue a transparent-to-color electrochromic supercapacitor. Still, the length of the alkyl chain affects the optical contrast and specific capacitance of the polymers. An ambipolar polymer with a butyl chain as linker displays the highest optical contrast and the best performance of specific capacitance at 291 and 394 F g–1 in the p-doping and n-doping regions, respectively. Finally, the ambipolar polymer was applied to fabricate a gel-type electrochromic device, which demonstrates a transparent-to-green switching during the charge/discharge process.

These electrodes are generally used for electrostimulation or electrophysiological recording. [2] To improve the signal transmission of these electrodes, electrode materials and their surface properties are key. To improve biocompatibility in relation to mechanical matching between tissues and electrodes, researchers are focusing on conducting polymers because of their stable electrochemical properties, soft nature, and strong biocompatibility. [3] The commercially available poly(3,4-ethylenedioxythiophene):poly( styrene sulfonate) (PEDOT:PSS) is among the most successful conducting polymers and is widely used because of its superior stability and ease of processing. [4] PEDOT exhibits mixed electronic and ionic conducting properties because it has a conjugated structure and is permeable to ions when immersed in electrolyte solutions, which improves charge injections at electrode surfaces and reduces electrochemical impedance when PEDOT is used to coat metallic electrodes. Many biomedical applications based on PEDOT and PEDOT:PSS have been demonstrated, including biosensors, [5] microelectrode arrays, [6] organic electrochemical transistors, [7] tissue engineering, [8] and brain-machine interfaces. [9] Biocompatibility and long-term stability remain major challenges for the application of PEDOT-coated implanted electrodes. The uncontrolled nonspecific binding and conformational change of proteins on PEDOT-coated electrodes can trigger foreign body reactions, leading to the malfunction and reduced lifetime of implanted electrodes. [10] Studies have presented modified PEDOT, mainly through the incorporation of peptides or growth factors during electropolymerization to improve the biocompatibility and long-term performance of PEDOT-coated electrodes. [11] Chemical modification through covalent bonding with functional groups on PEDOT coating has also been used to modify the PEDOT surface. In this process, EDOT monomers with functional groups are first designed and chemically synthesized. After electropolymerization to form PEDOT coating with these functional groups, surface modification can be further progressed through bioconjugation reactions with target biomolecules. [12] More recent studies have revealed that the incorporation of zwitterionic Poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives have demonstrated potential in the development of bioelectrodes because of their superior conductivity. However, developing reliable implanted bioelectrodes requires improvements in biocompatibility and the prevention of nonspecific adhesion. In this study, a six ethylene glycol (EG)-functionalized EDOTs with three different EG lengths (tri-EG, tetra-EG, and hexa-EG) and two types of end groups, hydroxyl (−OH) and methoxy (−OCH 3 ) is synthesized and systematically investigated. By coating them on gold electrodes using electropolymerization, the surface and electrochemical properties of these functionalized PEDOT-coated electrodes are investigated. Although PEDOT with −OH groups on the surface is more hydrophili...

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The copolymer films of corannulene-carbazole (CCZ) and 3,4-ethylenedioxythiophene (EDOT) were developed and applied to near-infrared (NIR) electrochromic window in this study. Two strategies were designed to improve the NIR electrochromic performance, including using a twisted structure and copolymerization. CCZ was selected as a twisted center due to its twisted polymer network after electropolymerization, which exhibited better NIR electrochromic performance, including faster response and higher stability, compared to planar carbazole-based materials. The electrochemical impedance analysis demonstrated the enhancing NIR electrochromism with the twisted structure originating from increasing ion transportation. In addition, EDOT, a monomer of a conjugated polymer, was employed to improve the optical contrast in the NIR region. The copolymer films were prepared in different feeding ratios of CCZ and EDOT, and the electrochemical properties and chemical composition of these copolymers were investigated. Finally, the copolymer films can exhibit the highest optical contrast (45% in 1000 nm) when a suitable ratio of EDOT to CCZ was used, indicating that introducing copolymerization with EDOT could further enhance the NIR electrochromism. This study gave critical insight into the molecular design of corannulene-based materials for electrochromic applications.