Композитные пленки на основе углеродных квантовых точек в матрице проводящего полимера PEDOT : PSS

Carbon quantum dots (CQDs) and their composites with the conducting polymer PEDOT: PSS were obtained by the hydrothermal method from glucose, and their electrical properties were investigated in the temperature range 77-280 K. CQDs have a globular structure with globule sizes of ~ 50 nm. The dependences of the resistivity on temperature,  (T), have been obtained for the films of CQDs, PEDOT:PSS-CQDs and PEDOT: PSS, which have a weak activation character. It was found that the  values of the CQD films are several orders of magnitude higher than the  values of the PEDOT: PSS films. It has been shown that with an increase in the content of CQDs in the PEDOT:PSS-CQDs composites, the (T) dependences exhibit a transition from high activation energies (~ 17-18 meV), characteristic of pure PEDOT: PSS, to lower values (~ 10 meV) observed in CQD films. The mechanism of transport of charge carriers in the investigated materials is considered.

Synthesis and Electrochromic Properties of Fluorescent PEDOT/PSS Composite

A novel kind of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) composite was synthesized through chemical oxidation polymerization in the presence of fluorescent yellow GG (FYGG) as the functional co-dopant and Poly(vinyl alcohol) as the film-forming additives. The as-prepared composite was found combined with fluorescent function and electrochromic property. Film of the PEDOT/PSS-FYGG composites switches from green in the reduction state to blue-green in the oxidized state, which is different from the pure PEDOT/PSS of light blue (-0.2V) and dark blue (0.8V). Because of the big molecule of FYGG as the dopant, the response time reaching 90% of the full optical contrast of PEDOT/PSS-FYGG was 1.77s for the coloration process and 1.78s for the reverse bleach process, which is a little slower than the pure PEDOT/PSS. Additionally, PEDOT/PSS-FYGG film presents a good stability. It is shown that acid dye doping is an effective method to broaden the color change range of the electrochromic mateials.

The Electropolymerization and Characterizations of Fluorescent Dye Doped Poly(3,4-ethylenedioxythiophene)

The electrochromic properties of an electrochemical polymerized composite consisted of poly (3,4-ethylenedioxythiophene) doped with fluorescent yellow dye (PEDOT-FY) are reported. The structures of PEDOT-FY were characterized via cycle voltammograms, spectroelectrochemistry and colorimetric analysis. Film of the PEDOT-FY composites with different FY concentrations appears multi-color changes, such as blue violet↔brillant blue, aubergine↔blue grey, magenta↔ aquamarine blue, orange-yellow↔grass-green, claybank↔moss green in the neutral state and the oxidized state respectively, which are different from the pure PEDOT of dark blue (-0.8V) and light blue (1.0V). The response time reaching 90% of the full optical contrast of PEDOT-FY was 3.4s for the oxidation process and 2.6s for the reverse reduction process when the [EDOT]/[FY] is 1:2, however, when the FY concentration decreased to [EDOT]/[FY] =1:0.01, the response time reduced to 1.9s and 1.7s for the oxidation and reduction process respectively, which is equal to that of the pure PEDOT. Additionally, the colorimetric analysis results show that components of yellow and red in PEDOT-FY films become stronger than pure PEDOT film at the whole electrochromic process. It is shown that acid dye doping is an effective method to broaden the color change range of the electrochromic mateials.