• Macromolecular Research
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• v.8 no.5
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• pp.224-230
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• 2000

Molecular mechanics technique has been used for finding energy-minimized conformation to understand the mechanism of yielding of glassy polymers in atomistic level. As a model polymer, amor- phous isotactic polypropylene (iPP) was generated by molecular mechanics and molecular dynamics methods. The stress-strain cone was successfully obtained by using molecular mechanics technique. The torsional angle distribution showed no significant change during extension, although the torsional angles of certain bonds in polymer backbone changed more largely than other bonds. No significant change in the van der Waals interaction is observed at yielding point, whereas the torsional angle energy starts to decrease at yield strain.

• Analytical Science and Technology
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• v.7 no.2
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• pp.181-186
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• 1994

Using poly(3-methylthiophene) conducting polymer film electrodes, feasiblity for Ag determination by stripping voltammetry has been studied. Ag ions accumulated by complexation with 18-crown-6, which are existing on the surface of the polymer film electrode, migrate inside of polymer film through potential scanning within limited potential range, and then are reduced and oxidized on the glassy carbon substrate. Therefore, the polymer film must have proper thickness and porosity for easy penetration of Ag ions. On the basis of these experimental results, $5.0{\times}10^{-6}M$ Ag(I) in aqueous solution could be determined.

• Journal of Korea Foresty Energy
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• v.18 no.2
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• pp.55-61
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• 1999

This study was carried out to investigate the influence of viscoelastic properties(or chemical composition) of a series of ethylen-viny1 acetate copolymers on impact noise and vibration damping of wood/polymer/wood sandwich composites. The impact noise and vibration damping of composites were very sensitive to the state of molecular motion of polymer. The noise and vibration damping of composites were maximum when the polymer was under the glass transition(vinylacetate 55~75%) at the test-temperature, and minimum rubbery state(vinyl-acetate 47~20%) or glassy state(vinylacetate 100~87%). The polymer under glass transition reduced the impact noise by 6~12 dB.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1919-1924
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• 2012

Poly(anthranilic acid) was synthesized by rapid mixing method using 5-sulphosalicylic acid as a dopant. The synthesized polymer was characterized by various techniques like FT-IR, UV-Visible, and X-ray diffraction $etc.$, The FT-IR studies reveal that the 5-sulphosalicylic acid is well doped within the polymer. The morphological property was characterized by field emission scanning electron microscopic technique. The electrochemical properties of the polymer were studied by cyclic voltammetric method. The synthesized polymer was used to modify glassy carbon electrode (GCE) and the modified electrode was found to exhibit electrocatalytic activity for the oxidation of uric acid (UA).

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.57-59
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• 2003

Molecular dynamics simulations have been performed on $\beta$-cyclodextrins octyl-derivative (b-CD) encapsulated into a polymer matrix of glassy poly(ether ether ketone) (PEEK-WC) material to investigate the effects of the complexation of p-nitrophenilacetate and naringin molecules with the aim to study the recognition properties of b-CD.

• Membrane Journal
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• v.7 no.4
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• pp.157-166
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• 1997

고분자를 크게 두가지로 대별해 보면 유리상 고분자(Glassy polymer)와 고무상 고분자(Rubbery polymers) 혹은 일레스토머로 나눌수가 있으며 이는 고분자의 유리전이온도(Glass transition temperature)에 따른 분류이다. 즉 유리전이온도가 상온 보다 높아 상온에서 유리상인 고분자를 유리상 고분자라 하고 유리전이온도가 상온보다 낮아서 상온에서 고무상인 고분자를 고무상 고분자라 한다. 이들 두 종류 고분자는 화학적 구조, 화학적 성질, 그리고 물리적 성질면에 있어서 상당히 다르다.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.115-120
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• 2003

Determination of iron(II) ion with a perfluorinated sulfonated polymer(nafion)-ethylenediamine(en) modified glassy carbon electrode was studied. It was based on the chemical reactivity of an immobilized layer(nafion-en) to yield complex $[Fe(en)_3]^{+2}$. The oxidation peak potential by differential pulse voltammetry(DPV) was observed at 0.340${\pm}$0.015 V(vs. Ag/AgCl). The linear calibration curve was obtained in iron(II) ion concentration range $5{\times}10^{-6}{\sim}0.2{\times}10^{-3} M(0.28{\sim}11.17\; mg/L)$, and the detection limit(3s) was $1.89{\times}10^{-5}$M(1.056 mg/L).

• Macromolecular Research
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• v.8 no.3
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• pp.103-115
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• 2000

The structural changes viewed from the molecular level have been investigated for the isothermal crystallization phenomena of polyethylene (PE) and the solvent-induced crystallization phenomenon of syndiotactic polystyrene (sPS) glassy sample. The data, which were collected by the time-resolved measurements of Fourier-transform infrared spectra, Raman spectra, synchrotron-sourced small-angle X-ray scattering, wide-angle X-ray scattering, and so on, were combined together to extract the detailed structural information in these phase transition phenomena. In the case of PE, the isothermal crystallization from the melt to the orthorhombic form was found to occur via the conformationally-disordered trans chain form, followed by the formation of the lamellar stacking structure of regular orthorhombic-type crystals. In the case of sPS, the amorphous chains in the glassy sample were found to enhance the mobility through the interaction with the injected solvent molecules, which act as a trigger to cause the conformational ordering from the random coil to the regular T$_2$G$_2$-type helical form. The thus created short helical segments were found to grow into longer helices, which gathered together to form the crystallites, as revealed by the organized coupling of the infrared, Raman and X-ray scattering data.

• Journal of Electrochemical Science and Technology
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• v.6 no.3
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• pp.81-87
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• 2015

This study introduces a facile strategy to prepare metal oxide/conducting polymer nanocomposites that may have promising applications in energy storage devices. Ploy aniline/nano wire manganese dioxide (PANI/NwMnO₂) was synthesized by cyclic voltammetry on glassy carbon electrode. Morphology and structure of the composite, pure PANI, MnO₂ nanowires were fully characterized using XRD and SEM analysis. Electrochemical studies shows excellent synergistic effect between PANI and MnO₂ nanowires which results in its capacitance increase and cycle stability against PANI electrode. Specific capacitances of PANI/NwMnO₂ and PANI were 456 and 190 F/g respectively. The electrochemical performance of electrodes studied using cyclic voltammetry, Galvanostatic charge/discharge and impedance spectroscopy.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3118-3122
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• 2010

The water soluble redox polymer, poly(N-vinylimidazole) complexed with Os(4,4'-dichloro-2,2'-bipyridine)$_2Cl]^+$ (PVI-[Os(dCl-bpy)$_2Cl]^+$), was electrodeposited on the surface of a glassy carbon electrode by applying cycles of alternating square wave potentials between 0.2 V (2 s) and 0.7 V (2 s) to the electrode in a solution containing the redox polymer. The coordinating anionic ligand, $Cl^-$ of the osmium complex, became labile in the reduced state of the complex and was substituted by the imidazole of the PVI chain. The ligand substitution reactions resulted in crosslinking between the PVI chains, which made the redox polymer water insoluble and caused it to be deposited on the electrode surface. The deposited film was still electrically conducting and the continuous electrodeposition of the redox polymer was possible. When cycles of square wave potentials were applied to the electrode in a solution of bilirubin oxidase and the redox polymer, the enzyme was co-electrodeposited with the redox polymer, because the enzymes could be bound to the metal complexes through the ligand exchange reactions. The electrode with the film of the PVI-[Os(dCl-bpy)$_2Cl]^+$ redox polymer and the co-electrodeposited bilirubin oxidase was employed for the reduction of $O_2$ and a large increase of the currents was observed due to the electrocatalytic $O_2$ reduction with a half wave potential at 0.42 V vs. Ag/AgCl.