• 폴리머
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• 제28권4호
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• pp.344-351
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• 2004

온도에 반응하는 고분자로서 폴리(에틸렌 글리콜)을 기본으로 다이블록 및 트리블록 폴리에스테르 공중합체들은 비독성과 생체적합성 그러고 생분해성 특징 때문에 주사제형의 약물전달체로서 많은 응용이 이루어지고 있다. 본 연구에서는 다이블록 공중합체를 이용한 새로운 솔-젤 전이 현상을 갖는 고분자를 준비하고자, 평균분자량 750g/mole의 메톡시 폴리(에틸렌 글리콜)과 카프로락톤을 실온에서 HCI $.$ Et$_2$O 존재 하에서 개환중합을 실시하였다. 합성된 고분자는 시차주사열량계와 X-선 회절기를 이용하여 특성을 분석하였고, 수용액상에서의 고분자 용액은 실온에서 신체온도로 온도를 상승시키면 졸에서 겔 상으로의 상변화를 보였다. 신체온도 부근에서의 겔 형성을 확인하기 위하여 20 W% 졸 상태의 고분자용액을 쥐의 피하에 주입한 결과 분산 없이 겔이 잘 형성되었고 2개월 간 겔이 유지됨을 확인하였다. 이러한 연구 결과로, 새로운 솔-젤 상전이 현상을 보이는 다이블록 공중합체를 합성하였고, 주사형 이식 재료로의 가능성을 확인하였다.

• 한국재료학회지
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• 제12권8호
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• pp.650-655
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• 2002

$SiO_2$ gels containing dispersed fine Te metal particles have been prepared by the sol- gel method using a starting solution containing Tetraethoxy Silane (Si($OC_2$ $H_{5}$ )$_4$), $H_2$O, Ethylalchol ($C_2$$H_{5}$OH), Nitric Acid ($HNO_3$) and Tellurium Tetracholoride ($TeCl_4$) in a several molar ratio. Gelling time of sols was about 3 days and viscosity of solution was very low about 2~3 cP for 3 days. Heat-treatments of the gel have been performed at 500, 700, 900, 1100 and $1300^{\circ}C$ for 1 hour, respectively. We have investigated TG-DTA, X-ray diffraction patterns and SEM of heat-treatmented gels. The size of Te fine particles dispersed in $SiO_2$ gel was about 0.8~1 $\mu\textrm{m}$ and the shape was almost quadrangle.

• 한국세라믹학회지
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• 제35권4호
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• pp.319-324
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• 1998

Sol-gel derived phosphate water-sioluble glasses containing Cu were prepared. Powder-shape of glasses were added in D.I water used polyethylene bottle. After solution contained glass powder were submerged in water bath on 25$^{\circ}C$ their dissolution behavior/characteristics bactericidal effect and cytotoxicity test were evaluated. The maximum amount of Cu(35 mol%) via sol-gel method was more 5 mol% increased than that with melting process. The stage of total dissolution was more dominant than that of selective leaching dur-ing dissolution due to dissolved amount of glasses increased linearly with time. The ratio of Cu+ to {{{{ {Cu }^{2+ } }} was 3:7 so that the structure of glasses is more predominant 2-dimension chain structure than 3-dimenshion po-lymeric structue. The stage of total dissolution was more dominant than that of selective leaching during dissolution. Bactericidal effect against all bacteria showed that solutions which contained 40 ppm and 100 ppm of Cu killed 80 percentages of bacteria within 2 hours and 100 percentages of those within 12 hours. The results of cytotoxicity test for L929 cells showed no cytotoxicity were observed within 96 hours for dis-solved solution that contains 40 ppm and 100 ppm of Cu.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.103-108
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• 2003

A method to determine chromium(III) ion in aqueous solution by chemiluminescence method using a lucigenin entrapped silica sol-gel film has been studied. An optical probe for chromium(III) ion has been prepared by entrapping lucigenin into silica sol-gel film coated on a glass support by dip coating. The chromium(III) optical sensor is based on the catalytic effect of chromium(IIII) ion on the reaction between lucigenin and hydrogen peroxide in basic solutions. The effects of Nafion, DMF and Triton X-100 were investigated to find the optimum condition to minimize cracking and leaching from the probe. The effects of pH and concentrations of lucigenin and hydrogen peroxide on the chemiluminescence intensity were investigated. The chemiluminescence intensity was increased linearly with increasing chromium(III) concentration from $2.5{\times}10^{-4}$M to $8.0{\times}10^{-7}$M and the detection limit was $4.0{\times}10^{-7}$M.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.806-808
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• 2008

We studied ink-jet printing for selective deposition of soluble oxide semiconductor to fabricate transistor. Sol-gel derived ZTO solution was synthesized for ink-jet printable solution. Transistors were produced by printing oxide layer between ITO electrodes. We demonstrated that ink-jet printed ZTO transistors work well and surface treatment significantly influences device performance.

• Macromolecular Research
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• 제10권3호
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• pp.174-177
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• 2002

Proton-conducting hybrid materials composed of silica and Nafion polymer were prepared from the sol-gel synthesis of silica in aqueous Nafion solution. The compositions of hybrid proton conductors were adjusted with the changing ratios of tetraethyl orthosilicate to Nafion. The thermal analysis, FTIR, SEM, and X-ray diffraction studies have proved the formation of Nafion/silica hybrid materials and no remarkable phase separation was observed, which led to an assumption that the macromolecular chain of silica and Nafion was homogeneously interlaned.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.2013-2014
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• 2011

Indium tin oxide (ITO) thin films have been deposited onto bare glass substrates by sol-gel process. The solution was prepared by mixing indium precursor and tin precursor dissolved in 2-methoxyethanol at $75^{\circ}C$ for 12 hours. Indium tin oxide films were prepared by slowly heat up to $200^{\circ}C$ for 10 minutes and annealed at $350^{\circ}C$ for 1 hour. In this paper, we researched simple and inexpensive sol-gel process. To find the optimal ratio of In/Sn to reduce electric resistance in ITO made by sol-gel process, we assessed electric properties varying the ratio of In and Sn precursor.

• Bulletin of the Korean Chemical Society
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• 제27권12호
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• pp.1981-1984
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• 2006

Novel amphiphilic, thermo-responsive polyaspartamides which showed both LCST (lower critical solution temperature), and sol-gel transition were prepared and characterized. The polyaspartamide derivatives were synthesized from polysuccinimide, the polycondensate of aspartic acid monomer, via successive nucleophilic ring-opening reaction by using dodecylamine and N-isopropylethylenediamine (NIPEDA). At the intermediate composition ranges, the dilute aqueous solution exhibited a thermally responsive phase separation due to the presence of LCST. The phase transition temperature was controllable by changing the content of pendent groups. In addition, a physical gelation, i.e. the sol-gel transition was observed from the concentrated solutions, which was elucidated by dynamic viscoelastic measurements. These novel injectable and thermo-responsive hydrogels have potential for various biomedical applications such as tissue engineering and current drug delivery system.

• 한국결정성장학회지
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• 제5권4호
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• pp.332-342
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• 1995

실리콘 알콕사이드 용액의 졸-겔 전이에 있어서 반응조건에 중요한 영향을 미치는 인자에 대하여 Raman 분광분석을 기초로 해서 고찰해 보았다. 촉매의 종류, 용매, 건조제어용 화학첨가제 및 물의 양과 같은 여러 가지 인자가 졸-겔 과정에 있어 전이메카니즘에 영향을 주었다.

• 한국결정성장학회지
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• 제22권1호
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• pp.15-18
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• 2012

Transparent conductive indium zinc oxide thin films were prepared by spin-coating a sol-gel solution. Zinc acetate dihydrate [$Zn(CH_3COO)_2{\cdot}2H_2O$] and indium acetate [In$(CH_3COO)_3$] were used as starting precursors, and 2-methoxyethanol with 1-propanol as solvents. Upon annealing in a temperature range from 500 to $1000^{\circ}C$, the thin film crystallizes into polycrystalline $In_2O_3$(ZnO). The lowest electrical resistivity was obtained at an annealing temperature of $700^{\circ}C$ as $2{\Omega}{\cdot}cm$. Average optical transmittances were higher than 80% at all annealing temperatures. These experimental results confirm that the sol-gel spin-coating can be a good simplified practical method for forming transparent electrodes.