• Macromolecular Research
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• 제10권4호
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• pp.215-220
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• 2002

The electrorheological (ER) and dielectric behaviors of the polypyrrole(PPy)-coated poly(ethyl methacrylate)(PEMA) suspensions in mineral oil were investigated. PPy was coated on PEMA particles to enhance the particle polarization, which would lead to the enhanced ER response. Various PPy-coated PEMA particles were synthesized by controlling the oxidant amount during the pyrrole polymerization, and the ER responses of their suspensions were investigated. The ER response initially increases with the oxidant amount, passes through a maximum, and then decreases with the oxidant amount. The initial increase in the ER response with oxidant amounts is due to the enhanced particle polarization with the increased particle surface conductivity. The dielectric properties of the corresponding suspensions support that the ER enhancement arises from the enhanced particle polarization. The decrease in the ER response at large oxidant amounts seems to arise from the increased conduction between the PPy-coated PEMA particles.

• Macromolecular Research
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• 제10권4호
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• pp.181-186
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• 2002

The displacement of carbon black to polypyrrole as a catalyst supporter in the fuel electrode of a direct methanol fuel cell was investigated. Polypyrrole was obtained as a black powder by the chemical polymerization of pyrrole with three different oxidants. The synthesized polypyrroles were pasted on carbon paper and transformed to the fuel electrodes with electrochemically deposited platinum. The prepared fuel electrode was assembled and mounted in a unit cell using a membrane and cathodic electrode film. In comparison with the carbon black fuel electrode, the performance of the unit cell was analyzed in relation to the state of the catalyst, the type of oxidant, and the morphology of the polypyrrole powder.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1107-1108
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• 2006

The coating of conductive polypyrrole (Ppy) on nonconductive ceramic substrates was performed by polymerization of pyrrole (Py) in an aqueous solution. The Ppy film was characterized by scanning electron microscopy and conductivity measurements. Electrophoretic deposition of bimodal alumina suspension prepared with a phosphate ester was performed using Ppy film as a cathode. Fabrication of alumina ceramics with irregular shapes or complicated patterns were also attempted by sintering the deposits together with the Ppy coated substrates in air.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1715-1718
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• 2009

A series of sitting-atop (SAT) complexes, [(ZrO)$H_2t(X)pp(NO_3)_2$], have been prepared via the reactions of free base meso-tetraarylporphyrins, $H_2$t(X)pp, with zirconyl nitrate hydrate, ZrO(N$O_3)_2{\cdot}xH_2$O. The products have been characterized by a variety of methods including $^1H\;NMR,\;^{13}C$ NMR, IR and UV-Vis spectroscopies, elemental analysis and conductance measurements. The data indicate that the meso-tetraarylporphyrins coordinate with two pyrrolenine nitrogen atoms to the zirconyl cation located above the distorted porphyrin plane and two protons remain on the pyrrole nitrogens. Such half sandwich-type sitting-atop complexes may be considered as models for the initial steps of the metallation of the macrocycles.

• Elastomers and Composites
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• 제34권4호
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• pp.299-314
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• 1999

Bonding metal and textile components to rubber has always posed a problem. In this paper, an attempt had been made to modify textile and metal surfaces for bonding with rubber. The metal surfaces were modified using silane coupling agents and textile fibers were modified using plasma polymerization techniques. Some results on adhesion of metals to a range of sulfur-cured rubber compounds using a combination of organofunctional silanes are given here. The treatment was not only effective for high-sulfur compounds but also for low-sulfur com pounds as used in engine mounts and even for some semi-EV compounds. Coatings of plasmapolymerized pyrrole or acetylene were deposited on aramid and polyester tire cords. Standard pull-out force adhesion measurements were used to determine adhesion of tire cords to rubber compounds. The plasma coatings were characterized by various techniques and the performance results are explained in an interpenetrating network model.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1840-1844
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• 2004

The mass spectra of benzophenones, 2-benzoylthiophenes, 2-benzoylpyrroles, and 2-benzoylfurans which have substituents at the m- and p-positions of the benzoyl ring were analyzed to find correlations against the Hammett substituent parameter ${\sigma}\;and\;{\sigma}^+$. The slopes of the plots of the intensities of the fragments from the heterocycles against those of the benzene gave sets of meaningful values for the indices of aromaticity of the heterocycles: benzene 1.00; thiophene 0.94, pyrrole 0.82, and furan 0.74.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.815-818
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• 2010

Free base meso-tetraarylporphyrins ($H_2T(X)PP$) react with tellurium(IV) chloride ($TeCl_4$) in mild conditions for formation sandwich intermediate sitting-atop (i-SAT) complexes, [$TeCl_4(H_2T(X)PP)_2$]. $^1H$ NMR, $^{13}C$ NMR, UV-vis, FT-IR and elemental analysis were used for characterization of the products. In the proposed structure of the i-SAT complexes, four pyrroles of each porphyrin ring are tilted alternatively up and down and this appropriates suitable orientation of lone pairs of two pyrrolenine nitrogens for electron donation to a tellurium center. $^1H$ NMR and FT-IR results showed that in the produced complex, hydrogen atoms of porphyrin macrocycles remained on the pyrrole nitrogens.

• 전기화학회지
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• 제14권1호
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• pp.22-26
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• 2011

Polypyrrole (Ppy) nanowire has been electrochemically synthesized via vertically oriented mesoporous silica template. The mesoporous template is also electrochemically deposited on indium tin oxide coated (ITO) glass from tetraethyl orthosilicate (TEOS) and cetyltrimethylammonium bromide (CTAB) surfactant. The highly ordered silica template is demonstrated to be 100~120nm thick with the pores of 4~5 nm diameter by scanning electron microscope (SEM) and transmission electron microscope (TEM). Ppy is formed to fill pores of the silica template from pyrrole solution by electrochemical oxidation. The Ppy in Ppy/silica/ITO composite was found to exhibit reversible electrochemical activity, as characterized by cyclic voltammetry (CV).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.529-532
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• 2001

We synthesized polypyrrole (PPy) by electrolysis of the pyrrole monomer solution containing support electrolyte KCl and/or p-toluene sulfonic acid sodium salt (p-TS). The electrochemical behavior was investigated using cyclic voltammetry and AC impedance. In the case of using electrolyte p-75, the redox potential was about -0.3 V vs. Ag/AgCl reference electrode, while the potential was about 0 V for using electrolyte KCl. It is considered as the backbone forms a queue effectively by doping p-TS Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. The AC impedance plot gave a tent of betterment of mass transport. PPy doped with p-TS has improved in mass transport, or diffusion. That is because the PPy doped with p-TS has a good orientation, and is more porous than PPy with KCl.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.909-912
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• 2000

We synthesized polypyrrole (PPy) nanotubules by oxidative polymerization of the pyrrole monomer within the pores of a polycarbonate template. The electrochemical behavior was investigated using cyclic voltammetry. The redox potential was about -0.5 V vs. Ag/AgCl reference electrode, while the potential was about 0 V for PPy film. It is considered as the backbone grows according to the pore wall. Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. By electrochemical doping of glucose oxidase (GOx) on PPy nanotubules, an enzyme electrode has been fabricated. The kinetic parameter of biochemical reaction with glucose was evaluated. The formal Michaelis constant and maximum current calculated by computer were about 11.4 mmol $dm^3$ and 170.85 A respectively. Obviously, an affinity for the substrate and current response of the PPy nanotubules enzyme electrode are rather good, comparing with that of PPy film.