• 한국분말재료학회지
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• 제29권3호
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• pp.207-212
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• 2022

Nanosized rutile titanium dioxide (TiO₂) is used in inorganic pigments and cosmetics because of its high whiteness and duality. The high quality of the white pigments depends on their surface coating technique via the solgel process. SiO₂ coatings are required to improve the dispersibility, UV-blocking, and whiteness of TiO₂. Tetraethyl orthosilicate (TEOS) is an important coating precursor owing to its ability to control various thicknesses and densities. In addition, we use Na₂SiO₃ (sodium silicate) as a precursor because of its low cost. Compared to TEOS, which controls the pH using a basic catalyst, Na₂SiO₃ controls the pH using an acid catalyst, giving a uniform coating. The coating thickness of TiO₂ is controlled using a surface modifier, cetrimonium bromide, which is used in various applications. The shape and thickness of the nanosized coating layer on TiO₂ are analyzed using transmission electron microscopy, and the SiO₂ nanoparticle behavior in terms of the before-and-after size distribution is measured using a particle size analyzer. The color measurements of the SiO₂ pigment are performed using UV-visible spectroscopy.

• 한국주조공학회지
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• 제22권3호
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• pp.114-120
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• 2002

A new titanium based alloy, Ti-10Ta-10Nb, has designed to examine the improved mechanical properties and biocompatibility. A specimen of titanium alloy was melted in a consumable vacuum arc furnace and homogenized at $1050^{\circ}C$ for 24 h. The effect of hot rolling on microstructure was estimated after rolling at $400^{\circ}C$ and $800^{\circ}C$ respectively. Surface of melted alloy by consumable vacuum arc melting was consisted of rough surface and it was changed to sound surface by coating of $ZrO_2$ slurry on copper mold surface. The hardness of Ti-10Ta-10Nb alloy increased with the amount of${\alpha}+{\beta}$ phase. Ti-10Ta-10Nb alloy showed $Widmanst{\"{a}}ten$ structure by hot rolling at $800^{\circ}C$ and in the rolling ${\beta}-region$ was negligible effects on microstructure refining.

• 한국세라믹학회지
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• 제45권8호
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• pp.472-476
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• 2008

The surface region of commercial stainless steel 304 and 316 plates has been modified through deposition of the multi-layered coatings composed of titanium film ($0.1{\mu}m$) and gold film ($1-2{\mu}m$) by an electron beam evaporation method. XRD patterns of the stainless steel plates deposited with conductive metal films showed the peaks of the external gold film and the stainless steel substrate. Surface microstructural morphologies of the stainless steel bipolar plates modified with multi-layered coatings were observed by AFM and FE-SEM images. The stainless steel plates modified with $0.1{\mu}m$ titanium film and $1{\mu}m$ gold film showed microstructure of grains of under 100 nm diameter. The external surface of the stainless steel plates deposited with $0.1{\mu}m$ titanium film and $2{\mu}m$ gold film represented somewhat grain growth of Au grains in FE-SEM image. The electrical resistance and water contact angle of the stainless steel bipolar plates modified with multi-layered coatings were examined with the thickness of the gold film.

• 대한치과보철학회지
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• 제54권2호
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• pp.120-125
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• 2016

목적: 본 연구는 in-vitro 상에서 recombinant human transforming growth factor-beta (rhTGF-${\beta}2$)와 poly(D,L-lactide-co-glycolide) (PLGA) 의 복합체를 티타늄 디스크 표면에 코팅하여, 생물학적으로 간엽줄기세포 증식에 미치는 영향을 조사하기 위해 시행되었다. 재료 및 방법: 양극산화 디스크에 일렉트로스프레이 코팅법을 이용하여 anodized 된 티타늄 디스크를 대조군으로 설정하고, rhTGF-${\beta}2$를 125 ng/ml와 500 ng/ml 농도로 코팅한 것을 실험군으로 하였다. 티타늄 디스크 표면에 분사된 복합체가 균일하게 분사되었는지 field-emission scanning electron microscopy (FE-SEM)을 통해 확인하였으며, atomic force microscope (AFM) test를 이용하여 rhTGF-${\beta}2$로 코팅한 디스크와 양극산화 디스크의 거칠기 차이를 확인하였다. 디스크 위에 간엽줄기세포 배양 후 1, 4, 7일에 세포증식 양상을 MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide) assay 검사를 통해 확인하였다. 결과: AFM 결과 대조군과 실험군에서 거칠기의 유의할만한 차이가 없었다 (P>.05). MTT 결과 7일차 배양 결과에서 125 ng/ml와 500 ng/ml PLGA/TGF-${\beta}2$처리된 그룹은 각각 평균 0.45와 0.48이였으며, 대조군은 평균 0.33으로 PLGA/TGF-${\beta}2$처리된 그룹에서 세포 증식이 더 활성화 되는 것을 확인할 수 있었다 (P<.05). 결론: rhTGF-${\beta}2$ 복합체를 electrospray법으로 코팅한 티타늄 표면에서 7일차에서 줄기간엽세포의 빠른 증식을 확인하였다. 또한 복합체 처리군의 농도가 증가할수록 높은 세포 성장 수치를 보였다.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.651-671
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• 2003

The influence of calcium phosphate (Ca-P) coating on the bone response of titanium implants was investigated two types of titanium implants, i.e. as -machined ,as -machined with Ca-P coating, were prepared. The Ca-P coating produced by OCT Inc technique. These implants were inserted into the left and right femur of beagle dog, After implantation periods of 3 days, 1weeks, weeks, 4weeks, 8weeks, 12weeks. 24weeks, the bone-implant interface was evaluated histologically, histomorphometrically , and removal torque. Histological evaluation revealed no new bone formation around different implant materials after 2weeks of implantation. After 4 weeks, Ca-P coated implants showed a higher amount of bone contact than either of the non coated implants. After 12weeks, bone healing was almost completed. And implant were removed by reverse torque rotation with torque-measuring device. Mean torque values for 4weeks control were 2.375Kgf.cm and experimental were 2.725Kgf.cm. And mean torque values for 8weeks control were 1.25Kgf.cm and experimental were 1.0Kgf.cm On the basis of these findings, we concluded that deposition of a Ca-P coating on an implant has a beneficial effect on the bone response to this implant during the healing phase. Besides implant surface conditions the bone response is also determined by local implant site condition.

• 한국수소및신에너지학회논문집
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• 제22권2호
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• pp.199-205
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• 2011

Stainless steel 304 and 316 plates were deposited with the multi-layered coatings of titanium film (0.1 um) and gold film (1-2 um) by an electron beam evaporation method. The XRD patterns of the stainless steel plates modified with the multi-layered coatings showed the crystalline phases of the external gold film and the stainless steel substrate. Surface microstructural morphologies of the stainless steel bipolar plates modified with multi-layered coatings were observed by AFM and FE-SEM images. The external gold films formed on the stainless steel plates showed micro structure of grains of about 100 nm diameter. The grain size of the external surface of the stainless steel plates increased with the gold film thickness. The electrical resistance and water contact angle of the stainless steel bipolar plates covered with multi-layered coatings were examined with the thickness of the external gold film.

• 한국표면공학회지
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• 제33권2호
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• pp.93-100
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• 2000

Effects of Ti content and Ti underlayer on the pitting behavior of TiN coated AISI 304 stainless steel have been studied. The stainless steel containing 0.1~1.0wt% Ti were melted with a vacuum melting furnace and heat treated at $1050^{\circ}C$ for 1hr for solutionization. The specimen were coated with l$\mu\textrm{m}$ and 2$\mu\textrm{m}$ thickness of Ti and TiN by E-beam PVD method. The microstructure and phase analysis were conducted by using XRD, XPS and SEM with these specimen. XRD patterns shows that in TiN single-layer only the TiN (111) Peak is major and the other peaks are very weak, but in Ti/TiN double-layer TiN (220) and TiN (200) peaks are developed. It is observed that the surface of coating is covered with titanium oxide (TiO$_2$) and titanium oxynitride ($TiO_2$N) as well as TiN. Corrosion potential on the anodic polarization curve measured in HCl solution increase in proportion to the Ti content of substrate and by a presence of the Ti underlayer, whereas corrosion and passivation current densities are not affected by either of them. The number and size of pits decrease with increasing Ti content and a presence of the coated Ti film as underlayer in the TiN coated stainless steel.

• 대한치과보철학회지
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• 제49권3호
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• pp.245-253
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• 2011

연구 목적: 양극 산화 티타늄 임플란트의 표면에RGD펩타이드를 화학적 고정 및 물리적 흡착 방법을 통해 코팅하고, 이러한 코팅방법에 따른 표면 변화와 펩타이드의 코팅여부, 인간간엽줄기세포 배양시의 부착, 증식, 분화를 비교하여, 펩타이드를 임플란트 표면에 코팅시키는 방법과 세포의 반응 간의 관계를 분석하고자 하였다. 연구 재료 및 방법: 직경 12.0 mm, 두께 3.0 mm의 양극 산화 티타늄 디스크 상에, 대조군은 아무런 코팅을 시행하지 않았으며, 실험군은 표면에 형광 물질이 고정되어 있는 RGD펩타이드를 화학적 고정 방법과 물리적 흡착 방법으로 코팅시켰다. 펩타이드 코팅 이후의 표면 변화를 살펴보기 위해 주사전자현미경관찰, 형광현미경 관찰, X-ray Photoelectron Spectrometry (XPS) 분석을 시행하였다. 세포 부착 정도와 형태의 변화 및 증식 정도를 평가하였다. 분화의 정도를 살펴보기 위해, 정량중합효소연쇄반응, alkaline phosphatase activity assay, alizarin red assay를 이용하여 각각 분석하였다. 통계 분석은 SPSS (ver. 17.0, SPSS, IL, USA)프로그램을 이용하여 Kruskal-Wallis test로 유의성을 검증하였고, 사후 검정은 Bonferroni test를 시행하였다(P=.05). 결과: 형광 현미경, XPS 분석 결과, 두 가지 코팅 방법에서 모두 펩타이드의 코팅이 확인되었으며, 물리적 흡착 방법이 화학적 고정 방법보다 더 많은 양의 펩타이드를 코팅시킬 수 있었다. 코팅 방법의 차이에 따른 세포의 초기 부착 정도와 형태 변화, 증식의 정도에는 유의할만한 차이가 나타나지 않았다(P>.05). 세포의 분화 정도는 물리적 흡착 실험군에서 대조군과 화학적 흡착 실험군에서보다 collagen type I과 osteocalcin, osteopontin의 양이 증가되었으며, ALP activity가 유의하게 증가되었다(P<.05). 결론: RGD-펩타이드를 양극 산화 임플란트에 코팅함으로써 인간간엽줄기세포의 반응에 영향을 주어 임플란트의 골유착을 증진시킬 수 있는 가능성을 확인하였으며, 특히 많은 양의 펩타이드를 코팅할 수 있는 물리적 흡착 방법이 화학적 고정 방법보다 인간간엽줄기세포 반응에 더 효과적임을 알 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권5호
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• pp.396-405
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• 2001

Osseointegrated implants are used for the fixation of dental prosthesis with good long-term clinical results. In an attempt to improve the quantity and quality of the bone-implant interface, numerous implant modification have been used. Implants surface modifications have been used such as titanium-plasma sprayed, hydroxyapatite-coating, sandblasted, sandblasted and acid-etched, acid-etched. Rough surface implants have greater implant surface area and enhance the bone-implant interface and improve stabilization. The purpose of present study was to evaluate light microscopic and scanning microscopic examinations and removal torque value of newly developed calcium phosphate blast and acid-etched implant in the femur of rabbits. Titanium plasma sprayed(TPS) implant served as controls. After 12 weeks of healing of the femurs of 12 rabitts, the implant-containing segments of femur were removed on bloc and bone block including sections. Histologic examination and histomorphometric and removal torque values comparision were made for two implants. Obtained results are follows: 1. Newly developed calcium phosphate blasted and acid-etched implants were in close contact with bone under light microscopic examinations. 2. New implants showed mean bone-to implant contact 59.8%, whereas TPS implants showed mean bone-to implant contact 54.5% (statistically no difference p<0.05). 3. New implants showed mean bone density 56.7%, whereas TPS implants showed mean bone density 49.2% (statistically difference p<0.05). 4. New implants demonstrated mean removal torque values 40.5Ncm, whereas the mean removal torque values of TPS implants ranged 39.3Ncm. No statistical differences(p<0.05) were observed between two groups of implants nor was there any difference between the two implants at the clinical level.

• Environmental Engineering Research
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• 제19권3호
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• pp.255-259
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• 2014

In this research, we compared the COD removal efficiencies of titanium dioxide ($TiO_2$) thin films coated on the surfaces of borosilicate glass that prepared by three different numbers of coating layer; i) 3 layers ii) 4 layers and iii) 5 layers by sol-gel method. All of the prepared $TiO_2$ thin films consisted of pure anatase crystalline structure with grain sizes in the range 20-250 nm. The calculated optical band gaps of the $TiO_2$ thin films were 3.24. The total apparent surface area per total weight of $TiO_2$ thin films were 4.74, 3.86 and $2.79m^2g^{-1}$ for 3, 4 and 5 layers coating, respectively. The kinetics of the photodegradation reactions of COD under UVA light source were described by the Langmuir-Hinshelwood (L-H) kinetic model. The specific rates of the photodegradation of $TiO_2$ thin films at 3 layers coating was $1.40{\times}10^{-4}min^{-1}mW^{-1}$, while for the 4 layers coating and the 5 layers coating were $1.50{\times}10^{-4}$ and $4.60{\times}10^{-4}min^{-1}mW^{-1}$, respectively. The photocatalytic performance of COD degradation was higher with smaller grain size, higher surface area and narrow optical band gaps. Moreover, the numbers of coating layer on substrate also have great influence for kinetic of COD removal.