• 유변학
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• 제11권2호
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• pp.91-96
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• 1999

반전도성 polyaniline의 유도체들로서 poly(aniline-co-sodium diphenylamine sulfonate), poly(aniline-co-o-ethoxyaniline), poly(o-methylaniline), poly(o-methoxyaniline)를 중합하여 전기유변유체의 입자로 사용하였다. 각 분산액은 전기장하에서 전형적인 전기유변특성을 나타냈으나, 낮은 전단변형률에서의 stress plateau 영역에서 입자의 종류에 따라 다른 흐름특성을 얻었다. 전기유변유체의 전기장에 따른 flow curve 변화와. dynamic yield stress와 전기장 간의 관계로부터 접근한 scaling law를 이용하여 각 전기유변유체의 universal flow curve를 구하였다.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.2111-2116
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• 2013

This paper reports substituent effects on the conformational changes in polyaniline (PAni) derivatives. PAni, poly-o-toluidine (POT), and poly-o-anisidine (POA) were formed by potentiodynamic electropolymerization in aqueous solution containing (+)-camphorsulfonic acid (CSA) as a dopant. UV-Vis spectroscopy and cyclic voltammetry measurements revealed that the methyl group showed a greater steric hindrance than the methoxy group. Further, the doping level decreased with increasing steric hindrance. The sign pattern of the circular dichroism (CD) bands for POA was opposite to that for PAni. However, no CD bands were observed in POT. The steric hindrance caused helical inversion, but at a high level of steric hindrance, the helical conformation could not be adopted, because of the reduced doping level. The reduced crystallinity was greatly affected by the decreased doping level. The steric effect influenced the polymer conformation and the doping level, thus determining the optical activity, morphology, and crystallinity of the PAni derivatives.

• KSTLE International Journal
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• 제7권1호
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• pp.18-21
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• 2006

The electrorheology of hollow PANI derivative suspensions in silicone oil was investigated by varying the electric fields and shear rates, respectively. The hollow PANI derivative susepnsions showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of chains upon application of an electric field. The shear stress for the hollow PANI succinate suspension exhibited an electric field power of 0.67. On the basis of the experimental results, the newly synthesized hollow PANI derivative suspensions were found to be an anhydrous ER fluid.

• Journal of Electrochemical Science and Technology
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• 제4권4호
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• pp.125-139
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• 2013

The electrical conductive polymers (ECPs) reported at my research group are introduced in this review, which works are started from the late Professor Su-Moon Park's pioneering research for polyaniline at the University of New Mexico. The electrochemical and spectroelectrochemical properties and their applications to sensor and energy conversion systems are briefly described. At first, the growth and degradation mechanism of polyaniline describes and we extend to polypyrrole, polyazulene, polydiaminonaphthalenes, and polyterthiophene derivatives. In addition, the preparation of monomer precursors having functional groups is briefly described that can give us many exceptional applications for several chemical reactions. We describe the application of these ECPs for the fabrication of chemical sensors, biosensors, biofuel cells, and solar cells.

• 한국재료학회지
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• 제15권8호
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• pp.543-547
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• 2005

Organic electroluminescence devices were made from 1,4-bis-(9-anthrylvinyl)benzene (AVB) and 1,4-bis-(9-aminoanthryl)benzene (AAB) anthracene derivatives. Device structure was ITO/AVB/PANI(EB)/Al (multi-layer device) and ITO/AAB:DCM/Al(single-layer device). In these devices, AVB, polyaniline(emeraldine base) (PANI(EB)) and AAB were used as the emitting material. 4-(dicyanomethylene)-2-methyl-6-p-(dimethylamino)styryl-4H -pyran(DCM) was used as red fluorescent dopant. We studied change of fluorescence wavelength with concentration of DCM doped in AAB. The ionization potential (IP) and optical band gap (Eg) were measured by cyclic voltammetry and UV-visible spectrum. We compared with difference of emitting wavelength between photoluminescence and electroluminescence spectrum. In case of the multi-layer device, PANI and AVB EL spectra have similar wave pattern to each PL spectrum and when PAM and AVB were used at the same time, and multi-layer device showed that a balanced recombination and radiation kom PANI and AVB. In case of the single-layer device, with the increase of DCM concentration, the blue emission decreases and red emission increases. This indicates that DCM was excited by the energy transfer from AAB to DCM or the direct recombination at the dopant sites due to carrier trapping, or both. The device with $1.0wt\%$ DCM concentration gave white light.