• 대한치과보철학회지
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• 제47권4호
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• pp.376-384
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• 2009

연구목적: 본 연구에서는 양극산화 임플란트 표면에 서로 다른 두 가지 방법, Ion beam-assisted deposition (IBAD)법과 Sol-gel법으로 Ca-P 코팅한 임플란트 시편에 골모세포를 배양하였을 때 세포의 증식, 분화, 형태에 어떠한 영향을 미치는지 조사하고자 한다. 연구재료 및 방법: 지름 10 mm, 두께 2 mm 인 상업용 순수 titanium grade IV 재질의 디스크를 제작하였고, 모든 시편은 acetone, 70% ethanol, 증류수에서 각각 10분씩 세척 후 건조하였다. 모든 표면은 300 V의 constant voltage하에서 양극 산화 (anodized)시킨다. 실험군은 양극산화 임플란트 표면에 각각 IBAD법과 Solgel법으로 Ca-P 코팅하였다. 각 표면의 미세표면 거칠기(Ra)를 측정하였고, SEM을 통해 표면의 형상을 관찰하였다. 골모세포을 배양한 후 각 표면군의 세포 증식, ALP 활성도 및 RT-PCR를 통한 골세포 분화 능력 검증을 하였으며, SEM을 통해 세포의 형상도 확인하였다. 통계분석은 SPSS (version 12.0) 프로그램을 이용하여 Kruskal-Wallis Test로 각 군의 유의성을 검증하였다 ($\alpha$=0.05). 결과: IBAD법으로 Ca-P 코팅한 표면이 Sol-gel법으로 Ca-P 코팅한 표면보다 표면 거칠기 (Ra) 값이 더 크게 나타났다 (P<.05). IBAD법으로 Ca-P 코팅한 표면이 Sol-gel법으로 Ca-P 코팅한 표면 보다 세포 증식이 더 활발하고 골세포 조기 분화 정도를 확인 할 수 있는ALP 활성도 또한 더 높게 나타났다 (P<.05). SEM 관찰 결과IBAD법으로 Ca-P 코팅한 표면에 골모세포들이 친화성을 띄면서 안정적으로 부착되었다. 결론: IBAD법으로 Ca-P 코팅한 표면이 Sol-gel법으로 Ca-P 코팅한 표면보다 더 우수한 세포 반응을 보였다. IBAD법으로 Ca-P 코팅한 표면의 세포들은 증식이 잘 이루어지고 잘 분화된 골모세포 형상을 보이고 ALP 활성도 또한 높아 골 형성을 증가시켜 높은 골-임플란트 접촉을 보일 것이다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.258-258
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• 2017

• 한국표면공학회지
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• 제51권6호
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• pp.393-399
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• 2018

Formation behavior of aluminum anodic oxide (AAO) films on Al6061 alloy was studied in view of thickness, morphology and defects in the anodic films in 20 vol.% sulfuric acid solution at a constant current density of $40mA/cm^2$, using voltage-time curve, observation of anodized specimen colors and surface and cross-sectional morphologies of anodic films with anodization time. With increasing anodizing time, voltage for film formation increased exponentially after about 12 min and its increasing rate decreased after 25 min, followed by a rapid decrease of the voltage after about 28 min. Surface color of anodized specimen became darker with increasing anodizing time up to about 20 min, while it appeared to be brighter with increasing anodizing time after 20 min. The darkened and brightened surfaces with anodizing time are attributed to an increase in thickness of porous anodic oxide film and a chemical damage of the films due to heat generated by increased resistance of the film, respectively. Cross-sectional observation of AAO films revealed the formation of defects of crack shape at the metal/oxide interface after 15 min which prevents the growth of AAO films. Width and length of the crack-like defect increased with anodizing time up to 25 min of anodizing, and finally the outer part of AAO films was partly dissolved or detached after 30 min of anodizing, resulting in non-uniform surface structures of the AAO films.

• 대한금속재료학회지
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• 제46권11호
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• pp.747-754
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• 2008

Recently, the requirement for the ultra thin copper foil increases with smaller and miniaturized electronic components. Therefore, it is important to examine the surface state of substrate depending on the processing parameter during the anodic oxidation. This study investigated the effect of the various electrolyte concentrations on anodizing of titanium anode prior to copper electrodeposition. Different surface morphology of anodized titanium was obtained at different electrolytic concentration 0.5 M to 3.0 M. In addition, the effect that the surfaces and the electrical characteristics on the electrodeposited copper layer was observed. In this study, surface anodized in the group containing 0.5M $H_2SO_4$ shows more uniform copper crystals with low surface roughness. the surface roughness and sheet resistance for 0.5M $H_2SO_4$ group were $1.353{\mu}m$ and $0.104m{\Omega}/sq$, respectively.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
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• pp.92-97
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• 2002

We establish a visible light emission from porous polycrystalline silicon nano structure(PPNS). The PPNS layer are formed on heavily doped n-type Si substrate. 2um thickness of undoped polycrystalline silicon deposited using LPCVD (Low Pressure Chemical Vapor Deposition) anodized in a HF: ethanol(=1:1) as functions of anodizing conditions. And then a PPNS layer thermally oxidized for 1 hr at $900 ^{\circ}C$. Subsequently, thin metal Au as a top electrode deposited onto the PPNS surface by E-beam evaporator and, in order to establish ohmic contact, an thermally evaporated Al was deposited on the back side of a Si-substrate. When the top electrode biased at +6V, the electron emission observed in a PPNS which caused by field-induces electron emission through the top metal. Among the PPNSs as functions of anodization conditions, the PPNS anodized at a current density of $10mA/cm^2$ for 20 sec has a lower turn-on voltage and a higher emission current. Furthermore, the behavior of electron emission is uniformly maintained.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.115.1-115.1
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• 2016

Electrochemical anodization has been interested due to its useful way for the nano-scale architecture of metal oxides obtained from a metal substrate. By using this method, it is easy to control the morphology of the oxide materials by controlling electrochemical conditions. Among oxide materials obtained from the transition metals such as Ti, V, W, etc., in this paper, the morphological study of anodized $TiO_2$ was employed at various voltage conditions in fluoric based electrolyte, and the effects of applied voltage (sweep rate and retention time) on the tube morphologies were investigated. Furthermore, by using anodization of tungsten substrate (W), we fabricated the porous structure of $WO_3$ and provided merits of tailored structure for the hybridization of inorganic and organic materials as electrochromic (EC) applications. The hybrid porous $WO_3$ shows multi-chromic properties during the EC reactions at specific voltage conditions. From these results, the anodization process with tailoring nano-structure is one of the promising methods for EC applications.

• 한국표면공학회지
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• 제23권1호
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• pp.34-43
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• 1990

Al-Si piston alloys such as AlS10CuMg have been anodized to examine apossibility of forming a hard film aat relatively higher temperatures compard with those in conventional sulfuric acid processes. Three types of electrolytes have been employed in this study ; electrolyte A(15% H2SO4, $0^{\circ}C$), electrolyte B(12% H2SO4, 1% oxalic, $10^{\circ}C$), electrolyte C(tartaric acid 125g/L+oxalic 75g/L+aluminum sulfate 225g/L, $25^{\circ}C$). Hard anodisine process in electrolyte B at a current density of 1.54A/dm2 produced a harder film of VHN 396 at a relatibely low film forming voltage compared with those obtained in other electrolyte at equivalent current density. A liner relationship between hardness and abrasion resistance exists for Al-Si piston alloys. The hardness of anodized film decreasees with increasing silicon content in Al-Si alloys and also with bath temperature. The film hardeness of Na-modified alloy os higher than that of P-modified alloy due to its finer microstructre. The film on the silicon phase in Al-Si alloys is observed to be formed by lateral growth of oxide film nucleated at surroundings.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.349-352
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• 2014

Anodic alumina oxide (AAO), a self-ordered hexagonal array, has various applications in nanofabrication such as the fabrication of nanotemplates and other nanostructures. In order to obtain highly ordered porous alumina membranes, a two-step anodization or prepatterning of aluminum are mainly conducted with straight electric field. Electric field is the main driving force for pore growth during anodization. However, impurities in aluminum can disturb the direction of the electric field. To confirm this, we anodized two different aluminum foil samples with high purity (99.999%) and relatively low purity (99.8%), and compared the differences in the surface morphologies of the respective aluminum oxide membranes produced in different electric fields. Branched pores observed in porous alumina surface which was anodized in low-purity aluminum and the size; dimensions of the pores were found to be usually smaller than those obtained from high-purity aluminum. Moreover, anodization at high voltage proceeds to a significant level of conversion because of the high speed of the directional electric field. Consequently, anodic alumina membrane of a specific morphology, i.e., meshed pore, was produced.

• 한국표면공학회지
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• 제41권1호
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• pp.16-22
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• 2008

Anodizing to form oxide layers on the pure titanium was performed in the electrolyte containing 1.5M $H_2SO_4$, 0.2M $H_3PO_4$, and 2.5wt.% $CuSO_4$ using the ac-biased arc anodizing technique. Titanium oxide layers anodized with different applied voltages, voltage-elevating rates, and anodizing times were investigated. In addition, thermal oxidation test under an atmospheric environment for the arc-anodized specimens was carried out. The thickness of oxide layers were not affected by the voltage-elevating rates, but increased slightly with the increase of anodizing times. The thickness of oxide layers were increased with the increase of voltages, and increased remarkably in the condition of 200V. The size and number of the pore observed in the center of the porous cell were decreased with increase of applied voltage. From the result of thermal oxidation test, it revealed that oxide layer formed by arc anodizing more effective to prevent oxidation of pure titanium.

• 한국표면공학회지
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• 제53권5호
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• pp.219-226
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• 2020

This paper investigated the characteristics of anodized aluminum 6061-T6 alloy for corrosion and stress corrosion cracking(SCC) under natural seawater. The hard anodizing oxide film formed on the 6061-T6 was a uniform thickness of about 25 ㎛. The corrosion characteristics were performed with a potentiodynamic polarization test. SCC was characterized by a slow strain rate tensile test under 0.005mm/min rate. As a result, the anodizing film showed no significant effect on SCC in the slow strain rate test. However, the corrosion current density of base metal was measured to be approximately 13 times higher than that of the anodized specimen. Therefore, the anodizing film significantly improved the corrosion resistance of 6061-T6 alloy in natural seawater.