RESUMEN

Rewritable paper has greatly promoted the sustainable development of society. However, the hydrophilicity/lipophilicity of the poly(3,4-ethylenedioxythiophene) (PEDOT) film limits its application as the rewritable paper. Herein, we constructed a repeatable writing/erasing pattern on a PEDOT film (rewritable PEDOT paper) by combining wettability control, water-induced dedoping, and an electrochemical redox reaction. The treatment with a medium-polarity/high-volatility solvent (MP/HVS) adjusted the wettability of the PEDOT film (water contact angle increased from 6.5° to 146.2°), contributing to the formation of a hydrophobic writable substrate. The treatment with a high-polarity solvent (HPS) induced the dedoping of anions in the PEDOT chain, resulting in the film's color changed from blue to purple and serving as a writing process. The intrinsic electrochemical redox (elimination of color change by doping/dedoping of lithium ions in the PEDOT chain) of the PEDOT film enabled the erasing process. This writing/erasing process can be repeated at least 10 times. The patterned PEDOT film maintained excellent stability to standing diverse solvents (low-polarity solvent (LPS) and MP/HVS), high temperatures (350 °C), and irradiation of different light wavelengths (wavelengths of 365, 380, 460, 520, and 645 nm). Additionally, the conductivity of the PEDOT film was quantitatively measured (impedance: LPS, increased 8.84%; MP/HVS, decreased 6.67%; and HPS, increased 27.97%) by fabricating a micropatterned PEDOT electrode. This work will provide a method for the fabrication of PEDOT-based optoelectronic functional materials.

RESUMEN

The structure and packing of organic mixed ionic-electronic conductors have an especially significant effect on transport properties. In operating devices, this structure is not fixed but is responsive to changes in electrochemical potential, ion intercalation, and solvent swelling. Toward this end, the steady-state and transient structure of the model organic mixed conductor, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), is characterized using multimodal time-resolved operando techniques. Steady-state operando X-ray scattering reveals a doping-induced lamellar expansion of 1.6 Å followed by 0.4 Å relaxation at high doping levels. Time-resolved operando X-ray scattering reveals asymmetric rates of lamellar structural change during doping and dedoping that do not directly depend on potential or charging transients. Time-resolved spectroscopy establishes a link between structural transients and the complex kinetics of electronic charge carrier subpopulations, in particular the polaron-bipolaron equilibrium. These findings provide insight into the factors limiting the response time of organic mixed-conductor-based devices, and present the first real-time observation of the structural changes during doping and dedoping of a conjugated polymer system via X-ray scattering.

RESUMEN

Cellulose aerogels have been widely studied as promising environmentally friendly materials due to their low density, biocompatibility and degradability. However, their applications are limited due to their highly combustible nature. In this study, polyaniline (PANI) decorated bacterial cellulose (BC) composite aerogel has been synthesized with in situ polymerization of aniline monomer on the surface of BC scaffold. The PANI decorated BC composite aerogel has a very high specific area of 124.0m2/g and well-preserved nanoporous structure, while its conductivity drastically increased to 10.44S/m. Interestingly, phosphate groups were incorporated onto PANI backbones due to its unique doping/dedoping structure. The resultant composite aerogel presented excellent flame retardancy, which can be self-extinguished within 1s. Moreover, PANI@BC composite hydrogel exhibited self-motion behavior under low voltage electric field, illustrating potential electromechanical actuator application. This simple and sustainable in situ doping method opens up new opportunities for cost-efficient fabrication of multifunctional cellulose-based electronics.

Asunto(s)

RESUMEN

UV (Ultra-Violet) light-driven change in optical absorption of polyaniline (PANI) is reported. Irradiation of UV light to PANI/camphor sulfonic acid prepared by electrochemical polymerization allows dedoping of the PANI. Especially, UV light irradiation in the presence of a radical trap agent effectively reduces (dedoping) the PANI. The result in this study is quite simple; however, this may be a first report for light-induced dedoping (color change) of a conductive polymer.