• Proceedings of the KSME Conference
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• 2003.04a
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• pp.55-60
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• 2003

Case that long-fiber reinforced polymeric composites of fiber orientation situation of a direction state is J=1 that is direction of tensile strength of another state appeared highest. And theoretical tensile strength value of long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state appeared similarly with tensile strength value that long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state. Also, than case that efficiency of fiber orientation situation of long-fiber reinforced polymeric composites is J=1 in it is J=0.1 of fiber orientation situation effect of long-fiber reinforced polymeric composites about 60% high appear.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1209-1213
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• 2005

Nuclear membrane is one of the main barriers in intracellular delivery of genetic materials. The previous report showed that glucocorticoid receptor dilated the nuclear pore to 60 nm in the presence of a ligand. It was also suggested that the transport of genetic material to nucleus might be facilitated by glucocorticoid. In this study, the effect of glucocorticoid preincubation in the polymeric gene delivery was investigated. The cells were preincubated with dexamethasone, a potent glucocorticoid, and transfection assays were performed with polyethylenimine (PEI) and polyamidoamine (PAMAM) dendrimer. As a result, the transfection efficiency of PEI or PAMAM to the cells in the presence of dexamethasone was enhanced, compared to the cells without dexamethasone. This effect was not observed in the cells preincubated with cholesterol. The polymer/DNA complex was stable in the presence of dexamethasone. In addition, the cytotoxicities of the polymeric carriers to the cells were observed in the presence of dexamethasone. In conclusion, dexamethasone enhances the transfection efficiency of polymeric carriers and may be useful in the development of polymeric gene carriers.

• Macromolecular Research
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• v.10 no.6
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• pp.345-358
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• 2002

The electrical conductivity during vulcanization process was measured as a function of time for the system of TiC loaded styrene-butadiene rubber (SBR) composites. The phenomenon of negative and positive temperature coefficients of conductivity and its conduction mechanism were also studied for the SBR polymeric composites. The current-voltage characteristics of the polymeric composites were non-linear in high voltage and showed a switching effect. The effects of temperature on the thermal conductivity and effective dielectric constant were measured. The measured parameters were found to be dependent on TiC concentration. The electromagnetic wave shielding (EMS) of the SBR-TiC polymeric composite was also examined. The SBR filled with TiC could be expected to be promising novel smart polymeric composites for self-electrical heating, temperature sensor, time delay switching, and electro-magnetic wave shielding effectiveness.

• Transactions on Electrical and Electronic Materials
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• v.4 no.3
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• pp.25-28
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• 2003

Radiation technology is an effective way for regulating polymeric materials to physicochemical and mechanical properties. New polymeric hydrogels based on vinyl ethers have been synthesized by the $\gamma$-initiated polymerization method. In this paper, we have studied the effect of radiation on mechanical and electrochemical properties of new rubber-like polymeric composite materials based on polyvinylether of ethyleneglycol (PVEEG).

• Journal of the Korean Chemical Society
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• v.22 no.3
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• pp.184-193
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• 1978

Various aluminum chloride polymeric catalysts have been prepared by the reaction of anhydrous aluminum chloride with styrene-divinylbenzene copolymer bead in the carbon disulfide solvent. The shapes of aluminum chloride polymeric catalysts have been investigated by the use of optical microscope, scanning electron microscope and analysis of atomic absorption and electron microprobe X-ray. The catalytic effect of aluminurn chloride polymeric catalysts in the process of esterification of various organic acids with several aliphatic and aromatic alcohols have been studied.

• Macromolecular Research
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• v.12 no.5
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• pp.437-442
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• 2004

We have fabricated a polymeric waveguide by using a hot embossing technique and have investigated its propagation loss. The replication of waveguide channels through the use of a hot embossing technique is of interest as a single-step process that could deliver surface roughnesses far smaller than the wavelength. We have evaluated experimentally that the sidewall roughness has a dominant effect on insertion losses of the multimode polymeric waveguide. The propagation loss of the waveguide decreased dramatically upon decreasing the sidewall roughness of the channel. We have confirmed that the preparation of waveguides having nanometer-scale sidewall roughness and 0.1 dB/cm propagation loss is possible when using the hot embossing technique.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.634-634
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• 2013

Transfer molding methods have a problem that weak adhesion between nanostructures and substrates. It is important to make various nano scale applications, also the stability of nanostructure on substrate is related with device performance. We studied an effect of poly 4-vinylphenol (PVP) as the polymeric adhesion layer between organic nanowires and a Si substrate when the nanowires are transferred by liquid-bridge-mediated nanotransfer molding method (LB-nTM). Their structural stability was examined by optical microscopy, scanning electron microscopy as multiple transfer molding and washing process. Field-effect transistors were fabricated with organic semiconductor nanowires on a polymeric adhesion layer and their electrical properties showed no significant difference as the one without the adhesion layer. As a result, adhesion layer can be used in the washing process and making multi-layer nano-scale patterns.

• Advances in materials Research
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• v.11 no.4
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• pp.331-349
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• 2022

In the present work, we proposed an analytical study on buckling behavior of a sandwich plate with polymeric core integrated with piezo-electro-magnetic layers such as BaTiO3 and CoFe2O4 reinforced by graphene platelets (GPLs). The Halpin-Tsai micromechanics model is used to describe the properties of the polymeric core. The governing equations of equilibrium are obtained from first-order shear deformation theory (FSDT) and the Navier's method is employed to solve the equations. The results show the effect of different parameters such as thickness, length, weight fraction of GPLs, and also effect of electric and magnetic field on critical buckling load. The result of this study can be obtained in the aerospace industry and also in the design of sensors and actuators.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.99-105
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• 1998

This research explored the feasibility of preparing and utilizing a preformed polymeric solution of Al(III) for coagulation in water treatment. Slow base(NaOH) injection into supersaturated aluminum chloride solutions did produce high yields of the type of Al polymers useful to water treatment applications. PACl's characteristic analysis showed that the quantity of polymeric Al produced at value of $r(OH_{added}/Al)=2.2$ was 83% of the total aluminum in solution, as showing maximum contents and precipitate was dramatically increased when r was increased above 2.35. And PACl was stable during sitoring period so aging effect was negligible. Results of the coagulation of Nakdong river waters with three PACls showed that the effectiveness of the three coagulants can be considered as r = 2.2 > r = 2.0 > r = 2.35 which are also the order of higher polymeric aluminum contents. Coagulation results for synthetic water exhibited optimum dose of 0.25mM Al, for three PACls, but above optimum dose, r = 2.0 and 2.2 PACl impaired the coagulation and sedimentation of turbidity and humic acid because of the restabilization of particulate. The effect of pH for on coagulation of Nak Dong River water showed that it had much effect turbidity and TOC removal, especially near pH 7. But pH effect was little for turbidity and TOC removal when r = 2.35 PACl was used for coagulation, that PACl had much more precipitates content.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.711-716
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• 1999

This research explored the feasibility of preparing and utilizing a prefonned polymeric solution of Al(III) for coagulation in water treatment. Slow base(NaOH) injection into supersaturated aluminum chloride and aluminum sulfate solutions did produce high yields of Al polymers useful to water treatment applications. The method of characterization analysis was based on timed spectrophotometer with ferron as a color developing reagent. The hydrolytic Al species were divided into $monomeric(Al_a),\;polymeric(Al_b),\;and\;precipitate(Al_c)$ from the difference in reaction kinetics. The analysis of PACl's characteristics showed that the quantity of polymeric Al produced at value of$ r(OH_{added}/AI)=2.2$ was $83\%$ of the total aluminum in solution, as showing maximum contents and precipitated Al was dramatically increased when r was increased above 2.35. In addition, the characteristics of polyaluminum sulfate (PAS) showed that polymeric Al contained at r = 0.75 was $18\%$ of the total aluminum in solution. The synthesized PACI and PAS were stable during storing period, as indicating negligible aging effect. The effect of sulfate ion on PACI was dependent on the concentration of sulfate ion. That is, polymeric species decrease and precipitate species increase as sulfate ion concentration increased. It can be concluded that the sulfate cause the formation of $Al(OH)_{3(S)}$ at low pH. However, The effect of calcium ion was negligible for distribution of Al species.