• 한국재료학회지
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• 제25권5호
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• pp.253-257
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• 2015

The implanting of metal products is performed with numerous surface treatments because of toxicity and adhesion. Recently, the surface modification of metal products has been actively studied by coating the surface of the TiC or TiN film. We prepared a Ti(10%)Ag Target which may be used in dental oral material by, using the AIP(arc ion plating) system TiAgN coating layer that was deposited on Ti g.23. The purpose of this study was to establish the optimal bias voltage conditions of the coated TiAgN layer formed by the AIP process. The TiAgN coatings were prepared with different bias voltage parameters (0V to -500V) to investigate the effect of bias voltage on their mechanical and chemical properties. The SEM(scanning electron microscope), EDS(energy dispersive X-ray spectrometer), XRD(X-ray diffraction), micro-hardness, and potentiodynamic polarization were measured and the surface characteristics of the TiAgN coating layers were evaluated. The TiAgN coating layer had different mechanical characteristics based on the bias voltage, which also showed differences in thickness and composition.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.374.2-374.2
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• 2016

Volatile organic compounds (VOCs) in the atmosphere are harmful materials which influence indoor air environment and human health. Titanium dioxide ($TiO_2$) is photocatalyst extensively used in degradation of organic compound. To improve the photocatalytic activity in the visible light region, doping with non-metals element or loading noble metals on the surface of $TiO_2$ is generally proposed. In this study, N- doped $TiO_2$ having photocatalytic activity in visible light region was attached noble metal such as Pt, Ag, Pd, Au by coupling method. Catalytic activities of Noble metal coupled $N-TiO_2$ powders were evaluated by the improvement of their photocatalytic activities and the degradation of VOC gas. A UV-Vis spectrophotometer was used to measure the diffuse reflectance spectra of coupled $N-TiO_2$ sample. The photocatlytic activities of as prepared samples were characterized by the decoloration of aqueous MB solution under Xenon light source (UV and visible light). To measure of decomposition VOCs, ethylbenzene was selected for target VOC material and the concentration was monitored under UVLED irradiation in a closed chamber system. Adjusting the initial concentration of 10~12 ppm, to evaluate the removal characteristics by using the coupled $N-TiO_2$.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3195-3198
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• 2014

An ultra-sensitive detection method for small molecules such as antibiotics was developed using ICP-MS with magnetic and $TiO_2$ nanoparticles. Since most of the antibiotics are too small to employ a sandwich-type extraction through an immunoreaction, a non-specific platform was employed, in which the target was extracted by magnetic separation, followed by tagging with $TiO_2$ nanoparticles of 11.2 nm for ICP-MS measurement. The detection limit for salinomycin obtained from spiked serum samples was $0.4ag\;mL^{-1}$ (${\pm}10.3%$), which was about $1.5{\times}10^6$ times lower than that of LC-MS/MS and about $1.2{\times}10^{11}$ times better than that of ELISA. Such an excellent sensitivity enabled us to study the toxicity of antibiotics exposed to human beings by determining them in serum.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.416-423
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• 2009

Hepatitis B core antigen(HBcAg) is an important serological marker used in the diagnosis of hepatitis B virus(HBV) infections. In the current study, a fast and efficient preparative purification protocol for truncated HBcAg from Escherichia coli disruptate was developed. The recombinant HBcAg was first captured by anion exchange expanded bed adsorption chromatography integrated with a cell disruption process. This online capture process has shortened the process time and eliminated the "hold-up" period that may be detrimental to the quality of target protein. The eluted product from the expanded bed adsorption chromatography was subsequently purified using size-exclusion chromatography. The results showed that this novel purification protocol achieved a recovery yield of 45.1% with a product purity of 88.2%, which corresponds to a purification factor of 4.5. The recovered HBcAg is still biologically active as shown by ELISA test.

• 센서학회지
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• 제8권1호
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• pp.10-15
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• 1999

ZnS 형광체와 BST 강유전체 박막을 절연층으로 사용한 백색방출 전계발광소자를 제작하였다. BST 박막의 제조조건으로 target의 조성비가 $Ba_{0.5}Sr_{0.5}TiO_3$이며, 기판온도가 $400^{\circ}C$, 분위기압이 30 mTorr, A:$O_2$의 비가 9:1일때 유전율이 1 kHz의 주파수에서 209를 나타내었다. 형광층으로 ZnS:Mn, ZnS:Tb 및 ZnS:Ag를 사용하였으며, 활성제 각각의 첨가량은 0.8, 0.8 및 1 wt%로 하였다. 형광층 전체의 두께가 500 nm로 하고 하부 절연층을 200 nm, 상부절연층을 400 nm로 증착하였을 때, 박막 전계발광소자의 발광문턱전압은 약 95 V 였고, 최고휘도는 150 V에서 약 $3000\;cd/m^2$이었다. 발광스펙트럼를 관찰한 결과 청색영역(450 nm), 녹색영역(550 nm) 그리고 적색영역(600 nm)의 파장에서 각각의 피이크가 나타나는 것을 관찰하였다.

• 센서학회지
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• 제10권6호
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• pp.295-303
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• 2001

형광체로서 ZnS를 사용하고 BST 강유전체 박막을 절연체로 사용한 전계발광소자를 제작하고 그 특성을 조사하였다. 형광체로는 청색 및 녹색발광을 위해 각각 $ZnS:AgF_3$와 ZnS:$TbF_3$를 사용하였으며 적색을 위해 ZnS:Mn과 $ZnS:SmF_3$를 사용했다. 이들의 형광체가 증착 도중에 분해되는 것을 막기 위해 석영관에 그들을 각각 봉입해서 열처리하여 결정화시킨 후에 진공증착원으로 사용하였다. 한편 절연층으로 사용한 BST박막은 $Ba_{0.5}Sr_{0.5}TiO_3$세라믹스 타겟을 사용하여 마그네트론 스퍼터링 방법으로 제조하였다. 이때 기판온도, 분위기압 및 작동기체인 $Ar:O_2$의 비가 각각 $400^{\circ}C$, 30 mTorr 및 9:1이였다. 각 형광체의 두께는 150 nm씩 합계 600 nm였고, 절연층은 상부가 400 nm 및 하두가 200 nm이었다. 이와 같이 만든 박막 전계발광소자의 발광 문턱전압은 $75\;V_{rms}$이고, 최고 휘도는 $100\;V_{rms}$에서 $3200\;cd/m^2$이었다. 그리고 절연층의 유전상수는 1 kHz에서 254이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.