• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.885-888
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• 2004

We have prepared and investigated the properties of photoinitiator-free photosensitive polyimide gate insulatos for organic thin-film transistors (OTFTs). The precursor was prepared from a dianhydride, 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (BTDA) and novel aromatic diamine, 7-(3,5-diaminobenzoyloxy) coumarine (DA-CM). Photo-patternability of the polyimide precursor film and surface morphology of the films before and after photo-patterning process were investigated and negative pattern with a resolution of 50 ${\mu}m$ was obtained nicely. In addition, we have fabricated OTFTs with pentacene and photosensitive polyimide as a semiconductor and a gate insulator; respectively. According to the device geometry, the ${\mu}$, current modulation ratio and subthreshold swing of the devices were around 0.2${\sim}$0.4 $cm^2$/Vs, more than $10^5$ and around 3${\sim}$5 V/dec, respectively.

• 한국환경보건학회지
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• 제41권1호
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• pp.17-23
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• 2015

Objectives: The cytotoxcities of Au, Ag, SWCNT, $SiO_2$, and ZnO nanomaterials were evaluated in order to assess their potential toxicological effects in in vitro cell models using colony forming efficiency (CFE) assay. Methods: The CFE assay of the test materials was carried out on Hep G2 cells. The size distribution of nanomaterials was studied by transmission electron microscopy (TEM). Changes in cell viability after treatment with a toxicant will result in a decreased number of colonies formed in comparison to solvent. Results: The TEM images show that all the particles except SWCNT and ZnO can be considered approximately spherical. The gold and $SiO_2$ nanoparticles show no response (no toxicity) in concentration response experiments. A statistically significant toxic effect was found in Hep G2 cells treated with Ag, SWCNT and ZnO nanomaterials. Conclusion: In this study, we considered CFE assay to be a promising test for screening studies for cytotoxicity with physicochemical analysis.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1505-1516
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• 2016

The detection of food pathogens is an important aspect of food safety. A range of detection systems and new analytical materials have been developed to achieve fast, sensitive, and accurate monitoring of target pathogens. In this review, we summarize the characteristics of selected nanomaterials and their applications in food, and place focus on the monitoring of biological and chemical contaminants in food. The unique optical and electrical properties of nanomaterials, such as gold nanoparticles, nanorods, quantum dots, carbon nanotubes, graphenes, nanopores, and polydiacetylene nanovesicles, are closely associated with their dimensions, which are comparable in scale to those of targeted biomolecules. Furthermore, their optical and electrical properties are highly dependent on local environments, which make them promising materials for sensor development. The specificity and selectivity of analytical nanomaterials for target contaminants can be achieved by combining them with various biological entities, such as antibodies, oligonucleotides, aptamers, membrane proteins, and biological ligands. Examples of nanomaterial-based analytical systems are presented together with their limitations and associated developmental issues.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.13-17
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• 2002

Ga$_2$O$_3$ nanomaterials were synthesized from mechanically ground GaN powders with thermal annealing Ga$_2$O$_3$ nanobelts were farmed in a nitrogen atmosphere, while Ga$_2$O$_3$ nanoparticles were formed inan oxygen atmosphere. The structural properties of the Ga$_2$O$_3$ nanomaterials were investigated by X-ray diffractometer (XRD) and high-resolution transmission eleotron microscope (HRTEM). The study of field emission scanning electron microscopy (FESEM) on the microstructures of nanomaterials revealed that the nanobelts are with the range of about 10∼200nm width and 10∼50nm thickness, and that nanoparticles are with the range of about 20∼50nm radius. On the basis of XRD and HRTEM data, we determined that the nanobelts grow toward a direction perpendicular to the (010) lattice plane and that they are enclosed by facets of the (10T) and (101) lattice planes. The formation of the nanobelts may be described by the vapor-solid(VS) mechanism, and the supersaturation device of gaseous phase may play an important role in the formation of Ga$_2$O$_3$ nanomaterials.

• 청정기술
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• 제22권1호
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• pp.1-8
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• 2016

최근 나노기술의 급격한 발전은 산업 분야에 새로운 활용 가능성을 제시하고 있다. 그러나 나노물질의 연간 생산량 증가와 함께, 비의도적인 환경 노출이 야기되고 있다. 따라서 지속적인 나노기술의 발전을 위해서도 나노폐기물에 관한 효과적인 관리가 필요하다. 나노폐기물 처리의 최종 단계는 바로 소각시설을 이용하는 것으로 보고 있다. 나노물질의 소각처리에 관한 문헌자료가 부족하지만, 일부 선도적인 연구자들에 의하면 소각시 나노물질의 대기노출은 억제되지만 바닥재는 결국 매립되어 나노물질은 잔존하게 된다는 것이다. 아직까지는 소각장내 나노물질의 거동과 다양한 질문거리가 남아 있지만, 무엇보다도 소각을 통한 나노폐기물 처리가 인간 및 환경 영향을 최소할 할 수 있는 안전하고 효과적인 나노물질 처리법인지가 검토되어야 할 것이다.

• 환경정책연구
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• 제12권3호
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• pp.49-71
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• 2013

독성, 환경 노출 및 인체에 대한 위해성 유해성 등 안전성에 대한 문제점을 가지고 있는 나노물질의 확인 및 안전성 확보의 요구가 점차 높아지고 있다. 나노물질은 화학물질로 이용될 뿐만 아니라 소비자가 이용하는 제품으로 범 분야에 걸쳐 활용되기 때문에, 보다 효과적인 나노물질의 안전관리 제도화를 위해서는 각국의 정책사례를 규제 강도별, 나노 적용분야별, 규제대상 종류별로 구분하여 정책 동향을 파악하는 것이 중요하다. 나노물질의 잠재적 위험성을 최소화시키기 위해서는 사전예방원칙을 적용한 제도의 구축 또한 필요하다. 더불어 국내 실정에 적합한 정책 수립을 목표로 하고, 국제 흐름에 선제적, 능동적으로 대응할 수 있는 방안도 함께 고려해야 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.152-152
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• 2013

Mechanism of energy conversion from chemical to electrical during exothermic catalytic reactions at the metal surfaces has been a fascinating and crucial subject in heterogeneous catalysis. A metal-semiconductor Schottky nanodiode is novel device for direct detection of chemically induced hot electrons which have sufficient energy to surmount the Schottky barrier. We measured a continuous chemicurrent during the hydrogen oxidation under of 760 Torr of O2 and 6 Torr of H2 by using Pt/Si and Pt/TiO2 nanodiodes at reaction temperatures and compared the chemicurrent with the reaction turnover rate. The thermoelectric current was measured by carrying out an experiment under O2 condition for elimination of the background current. Gas chromatograph and source meter were used for measurement of the chemical turnover rate and the chemicurrent, respectively. The correlation between the chemicurrent and the chemical turnover rate under hydrogen oxidation implies how hot electrons generated on the metal surface affect hydrogen oxidation.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1411-1414
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.507-508
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• 2012

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.893-896
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• 2012

Using molecular dynamics simulation method, we studied the carbon nanotube (CNT) non-covalently interacting with a polymer. As the polymer coiled around the CNT, the diameter of CNT deformed by more than 40% of its original value within 50 ps. By considering three different polymers, we conclude that the interaction between the CNT and polymer is governed by the number of repeating units in the polymer, not by the molecular weight of polymer.