• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.812-817
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• 1995

세슘의 고정화재료로서 Si/Al의 몰비가 약 2인 석탄화력발전소 산업폐기물인 fly ash와 CsNO$_3$의 반응이 열중량 분석기, 시차 열분석기 및 X-ray 회절분석기를 이용하여 공기분위기에서 수행되었다. X-ray 회절 분석결과 fly ash는 mullite와 quartz로 되어 있었고, fly ash와 세슘과의 반응물인 pollucite(CsAlSi$_2$O$_{6}$)의 생성이 확인되었다. 따라서 기상의 세슘화합물을 효과적으로 제거하기 위한 포집제의 원료물질로서 fly ash의 이용 가능성을 확인하였다.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.8-14
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• 2008

The effects of calcium type catalysts addition on the thermal decomposition of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) resin have been studied in a thermal analyze. (TGA, DSC) and a small batch reactor. The calcium type catalysts tested were calcinated dolomite, lime, and calcinated oyster shell. As the results of TGA experiments, pyrolysis starting temperature for LDPE varied in the range of $330{\sim}360^{\circ}C$ according to heating rate, but EVA resin had the 1st pyrolysis temperature range of $300{\sim}400^{\circ}C$ and the 2nd pyrolysis temperature range of $425{\sim}525^{\circ}C$. The calcinated dolomite enhanced the pyrolysis rate in LDPE pyrolysis reaction, while the calcium type catalysts reduced the pyrolysis rate in EVA pyrolysis reaction. In the DSC experiments, addition of calcium type catalysts reduced the melting point, but did not affect to the heat of fusin. Calcinated dolomite reduced 20% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of calcinated dolomite and lime enhanced the yield of fuel oil, but did not affect to the distribution of carbon numbers.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.596-602
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• 2006

The effects of resin additives and inorganic compounds addition on the thermal decomposition of low density polyethylene(LDPE) resin have been studied in a thermal analyzer(TGA, DSC) and a small batch reactor. The silica-alumina type compounds tested were kaolinite, bentonite, perlite, diatomaceous earth, activated clay and clay. The resin additives were antiforgging-agent and longevity-agent. As the results of TGA experiments, addition of antifogging-agent, longevity-agent and clay increased the temperature of the maximum reaction rate($T_{max}$). The silica-alumina type inorganic materials increased the pyrolysis reraction rate in the order of activated clay, diatomaceous earth, bentonite, perlites, and kaolinite. In the DSC experiments, addition of antifogging-agent and clay decreased the heat of fusion and the heat of pyrolysis reaction. Bentonite decreased 20% of the heat of fusion and 25% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of clay retarded the initial producing rate of fuel oil, but increased the yield of fuel oil. Addition of bentonite increased the yield of fuel oil from LDPE resin. Mixing of antifogging-agent and longevity-agent produced the fuel oil having lower carbon number. The amounts of the carbon number below 12 in fuel oil decreased with adding the clay. That below 23 in fuel oil increased with mixing of bentonite, perlite, kaolinite, and activated clay. But the mixing of diatomaceous earth did not affect the carbon contents of fuel oil from pure LDPE resin. In the silica-alumina type inorganic material used in this experiments, bentonite was the most effective from the pyrolysis heat, yields, and the characteristics of fuel oil.

• The Korean Journal of Rheology
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• v.7 no.3
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• pp.250-260
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• 1995

스크류 압출기로 제조한 poly(ether ether ketone) (PEEK)과 p-hydroxy benzoic acid/poly(ethylene tere-phthalate) (HBA/PET)의 공중합체인 열방성 액정 고분자의 블렌드 를 전조성에 대하여시차 주사 열분석기 (DSC)와 주사전자현미경(SEM)을 이용하여 연구하 였다. 측정된 유리전이 온도와 유리전이 온도에서의 열용량 증가분으로부터 PEEK가 액정고 분자에 녹아들어가는 양보다 액정 고분자가 PEEK에 녹아들어가는 양이 더 많음을 알수 있 었다. 고분자-고분자상호작용계수($\chi$12)값은 35$0^{\circ}C$에서 0.069$\pm$0.004이었고, 짝상에서 액정고 분자의 degree of disorder는 PEEK의 질량분율이 증가함에 따라 증가하였다. 블렌드에서 PEEK의 결정화에 액정 고분자는 거의 영향을 주지않았고 액정 고분자의 결정화 역시 PE 따에 영향을 받지 않았다. 모폴로지연구에서는 액정 고분자를 PEEK에 10%첨가시에 PEEK 의 메트릭스상에서 액정 고분자가 신장된 타원형을 형성하였으며 액정 고분자를 20% 첨가 시에는 액정 고분자가 섬유상구조를 가지고 있었다.

• The Korean Journal of Rheology
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• v.6 no.2
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• pp.96-103
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• 1994

열방성 액정 고분자인 백트라와 폴리페닐렌 설파이드와의 블렌드를 주사전자현미경, 시차주사 열분석기, 그리고 모세관 레오미터를 이용하여 전 조성 범위에 대하여 연구하였다. 블렌드의 결정화와 용융에 관한연구결과로부터 두 고분자 사이에는 상호작용이 없음을 알수 있다. 이는 두 개의 상이 완전히 분리되기 때문이다. 폴리페닐렌설파이드를 많이 포함하고 있는 블렌드의 점도는 상당히 감소되었으며 이는 높은 전단속도에서 열방성 액정 고분자가 섬유구조를 갖기 때문이다. 열방성 액정고분자의 섬유구조는 열방성 액정 고분자가 섬유구 조를 갖기 때문이다. 열방성 액정 고분자의 섬유구조는 열방성 액정 고분자와 등방성상과의 점도비와 전단속도에 의해 영향을 받음을 알수 있다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.424-424
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• 2013

Ce3+, Sm3+, Eu3+, Tb3+ 등 희토류를 도핑한 여러 종류의 형광체는 백색 LED (white light-emitting diode), 전계방출표시소자(field emission display), 플라즈마디스플레이패널(plasma display panel), 약물 운송(drug delivery) 등 다양한 분야에서 응용되고 있다. 최근에는 졸-겔 방법(sol-gel method)을 이용하여Y2SiO5, Y3-XGdxAl5O12, SrAl2O4 등 여러 종류의 호스트 물질을 합성하여 형광체의 특성을 분석하는 연구가 활발히 진행되고 있다. 이러한 졸-겔 방법은 비교적 낮은 온도에서 간단한 공정으로 좋은 균질성과 높은 생산성을 갖도록 형광체를 제작할 수 있는 장점을 가지고 있다. 이에 본 연구에서는 졸-겔 방법을 이용하여 BaGd2TiO13구조를 제작하였고, 이러한 구조적, 광학적 특성을 분석하기 위하여 열분석기(thermal analyzer), 전계방출형주사전자현미경(field emission scanning electron microscopy), 투과전자현미경(field emission transmission electron microscopy)을 이용하였다. 이러한 졸-겔 방법을 이용하여 제작한 BaGd2TiO13 구조의 형광체 적용 연구를 통한 디스플레이 및 백색 LED 응용에 유용할 것으로 기대된다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.2
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• pp.168-174
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• 2002

In order to obtain a new heat transfer fluid having a high thermal capacity, micro-capsules of a phase-change material can be a successful candidate to be added into water. In this study, 25, 50, 100, and $200\mu$m diameter micro-encapsulated Lauric acids were tested by a differential scanning calorimeter. The Lauric acid itself had a single freezing curve, but the micro-encapsulated Lauric acid had double freezing curves. The second freezing dominated for $25\mu$m diameter Lauric acids. But the first freeing energy became big as the size of the capsule increased.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.516-521
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• 1992

Hydroxypropyl chitin (HPCH) was prepared by reacting chitin with propylene oxide. HPCH showed the improved solubility in several organic solvents compared with chitin. It showed the remarkable solubility in formic acid. Form the results of polarized microscopic observatoin of HPCH solution in formic acid, finger-print pattern was observed in concentrations over 30 wt% solution. Since no typical thermogram was observed in DSC scan, the HPCH showed a lyotropic cholestric liquid crystallinity.

• Journal of the Korean Institute of Gas
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• v.2 no.4
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• pp.18-24
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• 1998

Polyurethane (PU) synthesized from 4,4'-diphenylmethane diisocyanate having high functionality (f=2.9) and polyester polyol have been investigated by differential scanning calorimeter (DSC), dynamic mechanical thermal analyzer (DMTA), and Fourier transform infrared spectroscope (FT-IR). From the DSC measurement of polyurethane, a single transition temperature ($T_g$) was observed. This result indicates that polyurethanes synthesized in this work have homogeneous network structure due to high functionality of diisocyanate. It was also found that the $T_g$ of polyurethane was increased as hard segment content was increased. The results from DMTA measurement are consistent with DSC results. In order to investigate the effect of thermal annealing on the $T_g$ of polyurethane, the samples were annealed at various annealing conditions. $T_gs$ of polyurethanes were found to increased with annealing temperature. From swelling experiment and FT-IR studies, it was found that the $T_g$ was increased as crosslinking density of polyurethane was increased.

• Korean Journal of Materials Research
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• v.2 no.6
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• pp.398-407
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• 1992

Cholesteryl S-alkoxybenzene thiocarbonates was synthesized and their liquid crystal transition temperature were determined. Those compounds exhibit enantiotropic cholesteric mesophases. The cholestric-isotropic transition temperatures decrease gradually with increasing alkoxy chain length and mesophase transition were investigated by differential scanning calorimetry.