Self-Formation and Anisotropic Electrical Conduction of Polypyrrole-Microtubes

Yan, Hu; Ishida, Tomoko; Toshima, Naoki

doi:10.1246/cl.2001.816

Cited by 14 publications

(9 citation statements)

References 13 publications

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“…6. Spontaneous formation of polypyrrole microtubes without any template during the electrochemical polymerization were previously reported [24][25][26][27]. In the cases, however, the microtubes do not array orderly and densely and the sizes of diameter and length are much larger than those in this work.…”

Section: 2mentioning

confidence: 56%

“…Conventionally, the conductive polymers are electrochemically synthesized as films with versatile surface features 2 depending upon the electrochemical reaction conditions [22]. Yan et al [24][25][26] an optical contact angle meter (Kyowa DropMaster 300) at room temperature and humidity. Raman spectrum was measured using a JASCO NR-1800 Laser Raman Spectroscopic System with a microscope.…”

Section: Introductionmentioning

confidence: 99%

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Super water-repellent poly(alkylpyrrole) films having environmental stability

Kurogi

Yan

Mayama

et al. 2007

Journal of Colloid and Interface Science

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Abstract:We present electrochemical synthesis of super water-repellent poly(alkylpyrrole) films which exhibit excellent environmental stability in terms of contact angle (> 150 o ) for water. The poly(alkylpyrrole) films synthesized under an optimized electrochemical condition consisted of thousands of micro-scaled 'needles' which densely aligned by shoulder to shoulder. The surface of the aligned 'needles' was analyzed by a box-counting method, to be a fractal structure with a dimension of 2.18.

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Section: 2mentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Super water-repellent poly(alkylpyrrole) films having environmental stability

Kurogi

Yan

Mayama

et al. 2007

Journal of Colloid and Interface Science

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“…No polymer film was formed by an applied potential of 800 mV vs. Ag/AgCl, by which polypyrrole microtubes were formed. 4,5 Polymer films were formed in the range of 5,000-7,000 mV vs. Ag/AgCl, but with relatively smooth morphology. From the applied potential of 8,000 mV vs. Ag/AgCl, polymer films with rough morphology were formed.…”

mentioning

confidence: 99%

“…4 The formed microtubes show unique properties, such as incandescence and extremely high thermal stability of the tube-shape.…”

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confidence: 99%

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Poly(1-n-octadecylpyrrole) Films with ‘Needle’-like Morphology

Yan

Hattori

Fujisato

et al. 2007

Polym J

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Electrochemical polymerization can provide conductive polymer films with various morphologies according to the reaction conditions. Therefore, the electrochemical polymerization was extensively studied using various kinds of monomers.1 Recently conductive polymers with unique shapes or their films with unique morphologies attract much attention due to their unique physical properties.2,3 Polypyrrole microtubes form during such electrochemical polymerization. 4 The formed microtubes show unique properties, such as incandescence and extremely high thermal stability of the tube-shape. 5Very recently, poly(alkylpyrrole) films with unique morphology were synthesized using a two-electrode electrochemical cell. [6][7][8] The polymer films show super water-repellency, 6,7 and those coated with fluorinated compound by a facile way have very high oil-repellency. 8 The excellent liquid-repellency is simply caused by the 'needle'-like morphology or fractal structure of the film surface. 7 The films have been mainly studied from the viewpoint of the liquid-repellency and its relevant properties. Poly(alkylpyrrole), however, can be considered as a kind of conductive polymers based on the nature of the molecular structure. Herein we report the synthesis of the polymer films using a three-electrode electrochemical cell, focusing on the optimum applied potential against reference electrode, Ag/AgCl. We also report electrochemical and electrical properties of thus-synthesized polymer films, and discuss the formation process of the 'needle'-like morphology.The poly(1-n-octadecylpyrrole) films were synthesized using three-electrode setup, in which indium-tin oxide (ITO) glass, platinum net, and Ag/AgCl were used as a working, counter, and reference electrode, respectively. The typical synthetic procedure was as follows: An acetonitrile solution of 1-n-octadecylpyrrole (5 mmol dm À3 ) and sodium p-toluenesulfonate (0.5 mmol dm À3 ) was electrochemically polymerized in a three-electrode cell at 9,000 mV vs. Ag/AgCl for 1 h. The polymer films were washed with acetonitrile and distilled water, and finally dried in vacuum overnight. The dried films were used for scanning electron microscopic (SEM), cyclic voltagramic (CV), and electrical conductivity measurements.SEM images of the films were obtained after gold-sputtering. CV curves were recorded using the films as a working electrode in an acetonitrile solution of sodium p-toluenesulfonate (0.5 mmol dm À3 ). Electrical conductivity of the films was measured by a conventional four-point technique.The poly(1-n-octadecylpyrrole) films were previously synthesized in a two-electrode cell. 6 The films were extensively studied in terms of water or oil-repellencies. [6][7][8] The surface structures of the films have mathematically fractal dimension of 2.2, based on analysis by a box-counting method.6,7 Such kind of solid surfaces with fractal structure interestingly influenced the cell cultures, which may provide potential biological applications. 9Ones can easily consider this polymer as a ki...

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