• Environmental Engineering Research
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• v.10 no.2
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• pp.45-53
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• 2005

Metal oxide particles with mole ratio of aluminum: titanium of 1:1 were synthesized by a sol-gel method. Langmuir (a) and Freundlich (b) adsorption isotherms of dissolved lead [Pb(Ⅱ)] ion on the metal oxide particles containing aluminum and titanium were determined as follows, respectively,(a) , (b) at pH 6where, correlation coefficients (R2) of Langmuir and Freundlich adsorption isotherms were 0.95 and 0.96, respectively.The overall adsorption rate of Pb(Ⅱ) on the metal oxide particles containing aluminum and titanium was determined by a differential bed reactor. The overall adsorption rate at pH 6 was as a following equation.at pH 6

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.382-383
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• 2007

PMMA plate with nano-sized pattern was synthesized on anodized aluminum oxide template by bluk polymerization method. Anodized aluminum oxide was used as a template to synthesize the PMMA plate with nano-sized pattern. The polymerization of MMA was performed at $75-79^{\circ}C$. It is verified from SPM results that the nano-sized pattern on synthesized PMMA plate was well transferred from that of anodized aluminum oxide template.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.194-195
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• 2006

Aluminum oxide films directly grown on n-type 6H-SiC(0001) substrates were fabricated by RF magnetron sputtering system. Metal-insulator-semiconductor(MIS) C-V properties with aluminum oxide thin films showed hysteresis and f1at band voltage shift. The dielectric constant of the film calculated from the capacitance at the accumulation region was about 5. Typical gate leakage current density of film at room temperature was the order of $10^{-9}\;A/cm^2$ at the range of within 2MV/cm. The breakdown did not occur at the film within the measurement range.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.102-102
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• 2010

One or two-dimensional nanostructures such as nanowires or nanomats have been widely uses as building blocks for nanoscale electronic devices. Nanofiber is one of sub-category of nano structures, it is easy to make nano-sized fiber by electrospinning technique. Nanofiber has large surface area as compared with their volume, it could be widely applied to many areas easily. Electrospinning technique is easy to control their structures and morphology safely and cost-effectively. We made nano-rings as a model of one dimensional nanostructures by electrospinning technique. To our knowledge, there were no reports on the preparation and investigation of alumina nano-rings by electrospinning technique. In this study, aluminum oxide nano-rings were produced after electospinning and calcination. The synthesized aluminum oxide nano-rings were characterized by scanning electron microscopy (SEM) to identify the morphology and the diameter of the ring, X-ray diffraction (XRD) to verify the crystallinity of the aluminum oxide, and X-ray photoelectron spectroscopy (XPS) for investigation of the chemical nature of the synthesized nano-rings.

• Bulletin of the Korean Chemical Society
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• v.16 no.9
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• pp.808-810
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• 1995

A strong SERS effect has been observed on silver surfaces which were prepared by Ag deposition in anodic aluminum oxide nanotemplates and subsequent partial removal of the oxide layers. The advantage of these surfaces for SERS studies is that the controlled size and dispersion of Ag particles can be achieved.

• Corrosion Science and Technology
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• v.21 no.3
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• pp.200-208
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• 2022

Aluminum alloy is used by adding various elements according to the needs of the industry. Aluminum alloys such as 5052 and 6061 are known to possess excellent corrosion resistance by adding Mg. Despite their excellent physical properties, corrosion can occur. To solve this problem, an anodization technique generally can improve corrosion resistance by forming an oxide structure with maximized hydrophobic properties through coatings. In this study, the anodizing technique was used to improve the hydrophobicity of aluminum 5052 and 6061 by creating porous nanostructures on top of the surface. An oxide film was formed by applying anodizing voltages of 20, 40, 60, 80, and 100 V to aluminum alloys followed by immersion in 0.1 M phosphoric acid for 30 minutes to expand oxide pores. Contact angle and corrosion characteristics were different according to the structure after anodization. For the 5052 aluminum, the corrosion potential was improved from -363 mV to -154 mV as the contact angle increased from 116° to 136°. For the 6061 aluminum, the corrosion potential improved from -399 mV to -124 mV when the contact angle increased from 116° to 134°.

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05a
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• pp.32-32
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• 1992

• Journal of the Korean institute of surface engineering
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• v.47 no.3
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• pp.121-127
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• 2014

In this study, in order to improve corrosion resistance and wear resistance of aluminum, surface treatment was made by anodizing with oxalic acid solution and sealing with nano-diamond powder. Average size of nano-diamond powder was 30nm. Anodizing with oxalic acid made many pores in the aluminum oxide layer. Pore size and oxide thickness were investigated by scanning electron microscope (SEM). Pore size increased as temperature increased and voltage increased. It was possible to make oxide layer with pore diameter more than 50 nm. Oxide thickness increased as temperature and voltage and treatment time increased. Oxide layer with above $10{\mu}m$ thickness was made. Aluminum oxide layer with many pores was sealed by water with nano-diamond powder. Surface morphology was investigated by SEM. After sealing treatment with nano-diamond powder, corrosion resistance, wear resistance and hardness increased.

• Biomedical Science Letters
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• v.14 no.2
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• pp.105-113
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• 2008

The objective of this study was to evaluate the influence of surface modifications on the bonding characteristics and cytotoxicity of specific titanium porcelain bonded to milling titanium and cast titanium. Milling titanium and cast titanium samples were divided into 8 test groups. These groups are as follow: i) sandblasted with particles of different size of $220{\mu}m\;and\;50{\mu}m$, ii) different sequences of sandblasting treatment and etching treatment, iii) etched with different etching solutions, and iv) preheated or not. The surface characteristics of specimens were characterized by the test of mean roughness of surface and SEM. The bond strength of titanium-ceramic systems was measured by using three-point bending test and SEM. The results show that the mean roughness of surface of sample sandblasted with $220{\mu}m$ aluminum oxide increased and bond strength were higher than sample sandblasted with $50{\mu}m$ aluminum oxide. The mean roughness of surface decreased, but the bond strength increased when the samples sandblasted with $220{\mu}m$ aluminum oxide were preheated. The sample sandblasted with $220{\mu}m$ aluminum oxide after oxidized with occupational corrosive agent I (50% NaOH, 10% $CuSO_4{\cdot}5H_2O$) and II (35% $HNO_3$, 5% HF) showed higher bond strength than sample oxidized with 30% $HNO_3$ after sandblasted with $220{\mu}m$ aluminum oxide. Group NaCuNF220SP (milling Ti: 35.3985 MPa, casting Ti: 37.2306 MPa) which was treated with occupational corrosive agent I (50% NaOH, 10% $CuSO_4{\cdot}5H_2O$) and II (35% $HNO_3$, 5% HF), followed by sandblasting with $220{\mu}m$ aluminum oxide and preheating at $750^{\circ}C$ for 1 hour showed the highest bond strength and significant differences (P<0.05). The method for modifying surface of titanium showed excellent stability of cells.

• Journal of the Korean institute of surface engineering
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• v.53 no.5
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• pp.249-256
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• 2020

As the size of manufacturing equipment for LCD and OLED displays increases, replacement of existing heavy stainless steel components with light metals, such as aluminum alloys, is being more important in semiconducting and display manufacturing industries. To use aluminum alloys for components in semiconducting and display industries, it is important to develop a new anodization method for improved performance of anodic oxide films than conventional anodization method based on sulfuric acid. In this work, optimum applied current density and the best sealing methods for anodic oxide films in 3% oxalic acid were explored. Experimental results showed 2.5 A/dm2 is the best applied current density for improved hardness and dielectric breakdown voltage. Sealing of the anodic oxide films further improved their hardness, dielectric breakdown voltage and resistance to HCl, by which application of anodic oxide films become applicable for components in semiconducting and display industries.