• Economic and Environmental Geology
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• v.32 no.3
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• pp.307-315
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• 1999

Four organic polymers were mixed with mothmorillonite. Two cationic polymers a hi로 molecular weight polyacrylamide (494C) and a low molecular weight polymer (587C).Two anionic polymers include a high molecular weight polymer (aerotil). Each clay supension series were allowed to stand for 24 hours and were centrifuged, and the clay plugs were washed and dried. The dried samples investigated by XRD, IR and CEC measurement. The suspended clay containing anionic polymers was not flocculated at any concentratuons of polymer. But the suspendions containing two cationic polymers were rapidly flocculated at almost all concentrations. the d(001) spacings of Na-montmorillonite after being with cationic polymer 587C show about 15$\AA$ suggesting the polymers may have entered the interlayer spaces. The polymer 494C-treated sample produced double peaks of about 12 and 15$\AA$ in XRD. It indicates that the high molecular weight polymer. And cationic polymer 494C may be adsorbed mainy on the outside surface of clay, and some polymers may peretrate into olny interlayers in the margin of montmorillonite particles because of its high molecular weught. CEC of polumer 587-treated sample was reduecd mmarkedly suggesting polymer blocks CEC sites. The d(001) spacings of Ca-montmorillonite after being treated with cationic polymers show about 15$\AA$ suggesting that the interlayer spaces have not been expanded. In the experiment using a dilute Ca-bearing solution, the suspended caly containinf anionic polymers was flocculated. The results indicate that the flocculation behavior of montmorillonite-polymer supension depends on not only polymer properties such as concentration, electric charge and molecular weight but also compositions of solvent.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1200-1203
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• 2004

We investigated the molecular aligning capability of a polymer layer containing ceramic nanoparticles which can be used as a gate insulator of organic thin-film transistors (OTFTs). Because of the enhanced dielectric properties arising from the nanoparticles and molecular aligning properties of the polymer, the composite layer provides excellent mobility characteristics of the OTFTs.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.283-283
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• 2006

Multigram-scale product exclusively containing magnetic carbon nanoparticles (MNCPs) with uniform size was successfully fabricated without a specific separation process. The iron-doped PPy nanoparticles were synthesized by micelle templating and used as the carbon precursor in order to generate MCNPs. The magnetic carbon nanoparticles possessed a microporous structure and exhibited ferromagnetic properties at room temperature. This approach may be an effective alternative to generate magnetic carbon nanoparticles against the conventional arc-discharge technique.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1564-1567
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• 2008

We demonstrate here a self-aligned printing approach that allows downscaling of printed organic thin-film transistors to channel lengths of 100 - 400 nm. A perfected down-scaled polymer transistors (L= 200 nm) showing high transition frequency over 1.5 Mhz were realized with thin polymer dielectrics, controlling contact resistance, and minimizing overlap capacitance via self-aligned gate configuration.

• Macromolecular Research
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• v.9 no.1
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• pp.66-70
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• 2001

In this work, we present the development of phase structure of the poly(methyl methacrylate)(PMMA)/ poly(vinylacetate)(PVAc) mixtures in ethyl acetate solution by light scattering. The PMMA/PVAc blends cast from ethyl acetate solutions exhibited fine "modulated structures" over broad blend composition ranges, which originated from the spinodal decomposition of the ternary polymer solutions at low polymer concentrations during the casting. The periodic distance was depended on the blend compositions and evaporation times.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.61-61
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• 2011

Polymer solar cells have become one of the rising next generation solar cells due to their potential for lightweight and bendable plastic solar modules. Recently, the power conversion efficiency of polymer solar cells has reached ~8 %, which can make ~6 % plastic solar modules when it comes to the modular aperture ratio of ~80 %. Although this efficiency is far behind that of conventional inorganic solar cells, the plastic solar modules are expected to create new energy market into which the inorganic solar modules could not make inroads. In the near future, the plastic solar modules can be integrated with consumer electronics that should overcome the regulation of energy consumption. For this application, the polymer solar cells should be fabricated in a variety of module shapes, which can be resolved by employing conventional and/or advanced coating and molding technologies of plastics products. In this tutorial, the fundamental aspect of polymer solar cells will be briefly introduced and then recent trends in terms of materials and devices will be reviewed together with showing recent results in organic nanoelectronics laboratory.

• Journal of the Korean Applied Science and Technology
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• v.19 no.4
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• pp.265-272
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• 2002

$CaCO_{3}$ absorbed sodium lauryl sulfate (SLS) surfactant was prepared, Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using styrene(St) as a shell monomer and potasium persulfate (KPS) as an initiator, We found that when $CaCO_{3}$; core prepared by adding 2,0 wt% SLS, $CaCO_{3}$ core/PSt shell polymerization was carried out on the surface of $CaCO_{3}$ particle without forming the new PSt particle during St shell polymerization in the inorganic/organic core-shell polymer preparation, The structure of core-shell polymer were investigated by measuring the degree of decomposition of $CaCO_{3}$ using HCl solution, thermal decomposition of polymer composite using thermogravimetric analyzer and morphology by scanning electron microscope.

• Polymer(Korea)
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• v.30 no.3
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• pp.187-195
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• 2006

Atomic force microscope (AFM)-based anodic oxidation lithography has gained great in forests in fabricating nanometer scale features on semiconductor or metal substrates beyond the limitation of optical lithography. In this article AFM anodic oxidation lithography and its organic resist layers are introduced based on our previous works. Organic resist layers of self-assembled monolayers, Langmuir-Blodgett films and polymer films aye suggested to play a key role in enhancing the aspect ratio of producing features, the lithographic speed, and spatial precision in AFM anodic oxidation lithography.

• Macromolecular Research
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• v.17 no.11
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• pp.912-918
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• 2009

An optically active diacid containing the L-histidine moiety was prepared by reacting pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic acid 1,2,4,5-dianhydride) 1 with L-histidine 2 in acetic acid, and was polymerized with several aromatic diamines 5a-g to obtain a new series of optically active poly(amide-imide)s (PAIs) using two different methods, such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$)/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/N,N-dimethylformamide (DMF) system as a condensation agent. The resulting new polymers 6a-g with inherent viscosity was obtained in good yield. The polymers were readily soluble in polar organic solvents, such as N,N-dimethyacetamide (DMAc), N,N-dimethyformamide (DMF), and dimethyl sulfoxide (DMSO). The obtained polymers were characterized by FTIR, specific rotation, elemental analysis as well as $^1$H-NMR spectroscopy and gel permeation chromatography (GPC). The thermal stability of the resulting PAIs was evaluated with thermogravimetric analysis techniques under a nitrogen atmosphere.

• Polymer Science and Technology
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• v.21 no.2
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• pp.167-174
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• 2010