Electrochromic Self-Electrostabilized Polypyrrole Films Doped with Surfactant and Azo Dye.

Two azo dyes, acid red 1 (AR1) and acid red 18 (AR18), were used alone or in combination with sodium dodecyl sulfate (SDS) for the electropolymerization of a pyrrole monomer. Polypyrrole (PPy) showed higher redox capacity when SDS and AR18 were used simultaneously as dopant agents (PPy/AR18-SDS) than when the conducting polymer was produced in the presence of SDS, AR18, AR1, or an AR1/SDS mixture. Moreover, PPy/AR18-SDS is a self-stabilizing material that exhibits increasing electrochemical activity with the number of oxidation-reduction cycles. A mechanism supported by scanning electron microscopy and X-ray diffraction structural observations was proposed to explain the synergy between the SDS surfactant and the AR18 dye. On the other hand, the Bordeaux red color of PPy/AR18-SDS, which exhibits an optical band gap of 1.9 eV, rapidly changed to orange-yellow and blue colors when films were reduced and oxidized, respectively, by applying linear or step potential ramps. Overall, the results indicate that the synergistic utilization of AR18 and SDS as dopant agents in the same polymerization reaction is a very successful and advantageous strategy for the preparation of PPy films with cutting-edge electrochemical and electrochromic properties.

Brønsted acidic ionic liquids: Innovative starch desizing agents.

The possibility of using a synthesized inexpensive Brønsted acidic ionic liquids for starch desizing of a textile substrate for the first time was investigated under different conditions in terms of temperature, concentration and treatment time. The samples evaluation was carried out by Fourier transform infrared spectroscopy, microscopic studies, Tegewa tests, measuring weight loss, tensile strength, wetting properties and changes in the samples shades. The results indicated that the ionic liquids have strong effect on the cotton fabric starch desizing (Tegewa 6 or higher) with no adverse effect on the samples strength and whiteness. Thus, it was revealed that proper ionic liquids could be counted as novel starch desizing agents and alternative for the enzymatic process. In addition, it was observed that the acidic ionic liquids because of their specific structure do not have negative aspects of common acidic processes with no sensitivities and drawbacks of enzymatic treatments.