• 대한치과보철학회지
• /
• 제44권5호
• /
• pp.617-627
• /
• 2006

Statement of problem: HA has been used as a coating material on Ti implants to improve osteoconductivity. However. it is difficult to form uniform HA coatings on implants with complex surface geometries using a plasma spraying technique. Purpose : To determine if Ti6Al4V sintered porous-surfaced implants coated with HA sol-gel coated and hydrothermal treated would accelerate osseointegration. Materials and Methods : Porous implants which were made by electric discharge were used in this study. Implants were anodized and hydrothermal treatment or HA sol-gel coating was performed. Hydrothermal treatment was conducted by high pressure steam at $300^{\circ}C$ for 2 hours using a autoclave. To make a HA sol, triethyl phosphite and calcium nitrate were diluted and dissolved in anhydrous ethanol and mixed. Then anodized implant were spin-coated with the prepared HA sols and heat treated. Samples were soaked in the Hanks solution with pH 7.4 at $37^{\circ}C$ for 6 weeks. The microstructure of the specimens was observed with a scanning electron microscope (SEM), and the composition of the surface layer was analyzed with an energy dispersive spectroscope (EDS). Results : The scanning electron micrographs of HA sol-gel coated and hydrothermal treated surface did not show any significant change in the size or shape of the pores. After immersion in Hanks' solution the precipitated HA crystals covered macro- and micro-pores The precipitated Ca and P increased in Hanks' solution that surface treatment caused increased activity. Conclusion : This study shows that sol-gel coated HA and hydrothermal treatment significantly enhance the rate of HA formation due to the altered surface chemistry.

• 한국산학기술학회논문지
• /
• 제7권3호
• /
• pp.465-470
• /
• 2006

코팅은 플라스틱의 표면의 물성과 렌즈의 광학적 성능을 높이기 위해 필요하다. Allyl diglycol carbonate계열 렌즈의 표면의 물성과 광학적 성능을 개선하기 위하여 3-glycidoxypropyltrimethoxysilane(GPTS), methyltrimethoxysilane(MTMS) 및 tetraethyl orthosilicate(TEOS)의 몰 비를 변화시켜 유-무기 하이브리드 재료로 사용하였다. Sol-gel 공정에 의한 flow코팅하여, $140^{\circ}C$에서 4시간 경화하였다. 코팅 렌즈는 투과율, 부착력, 연필경도, 내마모성, 내온수성 및 내약품성을 평가하였고 GPTS, MTMS 및 TEOS의 몰 비가 각각 1:1:2일 때 가장 우수한 것으로 나타났다.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제11C권2호
• /
• pp.18-22
• /
• 2001

The thin films of high permitivity in ferroelectric materials using a capacitor are applied to DRAMs and FRAMs. (Ba, Sr)TiO$_3$ thin as ferroelectric materials were prepared by the sol-gel method and made by spin-coating on the Pt/Sio$_2$/Si substrate at 4,000 [rpm] for 10 seconds. The structural characteristics of the surface were analyzed by fractal dimension. The thickness of BST ceramics thin films was about 260∼280 [nm]. The property of the leakage current was stable with 10-9∼10-11[A] when the applied voltage was 0∼3[V]. BST thin films ha low leakage current properties when fractal dimension was low and a coating area was high.

• 전기화학회지
• /
• 제12권3호
• /
• pp.251-257
• /
• 2009

In this study, we fabricated nickel oxide thin film for lithium based electrolyte using sol-gel method. This film was deposited by dip-coating method with mixed solvent of DameH (N,N-dimethylaminoethanol) and DI water. As changing the ratio between DmaeH and DI water, nickel oxide thin film was presented in different charge density and optical transmittance because they were shown various thickness. It was accounted for changing viscosity and density by the ratio of DmaeH and DI water. The thin film synthesized with 1 : 1 ratio of DmaeH and DI water was expressed best electrochromic performance in lithium based electrolyte, because of thick thickness but porous structures.

• 한국안광학회지
• /
• 제13권1호
• /
• pp.37-42
• /
• 2008

목적: 플라스틱 렌즈에 착색이 가능한 하드코팅을 실시하고, 이 코팅의 분광 및 표면 특성을 평가하는데 있다. 방법: 코팅은 TEOS, MTMS과 GPTS를 이용한 졸-겔법으로 실시하였다. 코팅의 광학적 그리고 구조적 특성을 주사 전자현미경, 라만분광, 적외선분광 및 자외선/가시광선분광으로 조사하였다. 결과: 이 코팅의 착색성은 일반적인 하드코팅에 비해 2배 높았다. 착색 가능한 하드코팅이 적용된 렌즈의 부착성, 내마모성, 내온수성 및 내약품성은 우수하였다. 연필 경도는 5H였으며, 코팅의 표면은 매끄럽고 균일하였다. 결론: 플라스틱 렌즈에 이 코팅 시스템의 적용으로 착색이 가능한 단단하고 안정된 표면을 부여할 수 있었다.

• 대한치과보철학회지
• /
• 제44권5호
• /
• pp.594-605
• /
• 2006

Statement of problem: Modification of titanium implant surface has potential to ensure clinically favorable performance that several surface modification technologies have been introduced. Among the methods. anodizing method and sol-gel hydroxyapatite coating method have gained much interest due to its roughness and chemical composition of the coating layer, but more of its biocompatibility result is required. Purpose : The purpose of this study was to compare bone-implant interface shear strength of four different surface treated implants as time elapsed. Resonance frequency analysis(RFA) and removal torque measurement methods were employed to measure implant stability at one week and six week after implantation. Material and method: A total of 80 screw-shaped implant [20 machined, 20 resorbable media blasted(RBM), 20 anodized, and 20 anodized+hydroxyapatite sol-gel coated] were prepared, and one of each group was implanted in the tibia of a New Zealand white rabbit that total 20 of them were used. In order to test the implant stability and implant-tissue interface contact changing in the bone bed, each 10 rabbit were sacrificed 1 week and 6 week later while resonance frequency and removal torque were measured. One-way analysis of variance and the Tukey test were used for statistical analysis. Results : The results were as follows. 1. There was no statistically significant difference of implant stability quotients(ISQ) value in RFA between individual groups after 1 week of implantation and 6 weeks(p>0.05). But, there was statistically significant increase of ISQ value in 6 weeks group compared to 1 week group(p<0.05). 2. There was no statistically significant difference in removal torque analysis between individual groups after 1 week of implantation and 6 weeks(p>0.05). but there was statistically significant increase in all 4 groups after 6 weeks compared to 1 week later(p<0.05). 3. There was no statistically significant difference in removal torque analysis between anodized group and HA coating after anodic oxidation 6 weeks later(p>0.05), but significant difference was appeared in both groups compared to RBM group and smooth-machined group(p<0.05). Conclusions : It can be suggested that changes in surface characteristics affect bone reactions. Anodized and anodized+hydroxyapatite sol-gel coating showed significantly improved bone tissue response to implants, but further study on the effect of hydroxyapatite dissolution is needed.

• Bulletin of the Korean Chemical Society
• /
• 제28권6호
• /
• pp.1015-1020
• /
• 2007

A simple approach to prepare arrays of Au/TiO2 composite nanoparticles by using Au-loaded block copolymers as templates combined with a sol-gel process is described. The organic-inorganic hybrid films with closely packed inorganic nanodomains in organic matrix are produced by spin coating the mixtures of polystyrene-block-poly(ethylene oxide) (PS-b-PEO)/HAuCl4 solution and sol-gel precursor solution. After removal of the organic matrix with deep UV irradiation, arrays of Au/TiO2 composite nanoparticles with different compositions or particle sizes can be easily produced. Different photoluminescence (PL) emission spectra from an organic-inorganic hybrid film and arrays of Au/TiO2 composite nanoparticles indicate that TiO2 and Au components exist as separate state in the initial hybrid film and form composite nanoparticles after the removal of the block copolymer matrix.

• 한국화재소방학회논문지
• /
• 제30권3호
• /
• pp.67-72
• /
• 2016

본 연구에서는 최근 사회적으로 이슈가 되고 있는 다중이용시설의 화재 시 건축자재로 사용되는 내장재의 가연성으로 인한 화재확산 및 연소 시 유독가스 발생으로 인한 인명피해를 사전 예방하기 위한 방염제를 개발하고자 한다. 유-무기 하이브리드 소재로 실리카 졸에 방염성을 부여할 수 있는 방염 소재를 적용하여 졸-겔법에 의한 방염 접착제 또는 코팅제를 제조하였다. 기존의 방염소재는 물론 비방염소재의 방염화를 비할로겐 방법으로 적용가능하며, 기존의 접착 코팅제의 기본 물성과 특히 내열성능을 높여 화재 시 내열성 및 내구성을 향상시킬 수 있기 때문에 건축자재의 비할로겐 방염화를 확대하고자 한다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.361-361
• /
• 2012

PZT (Pb(Zr,Ti)O3) thin films have been used widely in the MEMS application, due to their inherent ferroelectric and piezoelectric properties. Such ferroelectricity induces much higher dielectric constants compared to those of the nonperovskite materials. In this work, the PZT thin films were deposited onto Indium-Tin-oxide (ITO) substrates through the spin-coating of PZT sols. The deposited PZT thin films were characterized in terms of the electrical and optical properties with special emphases on conductivity and optical constants. The detailed analysis techniques incorporate the dc-based current-voltage characteristics for the electrical properties, spectroscopic ellipsometry for optical characterization, atomic force microscopy for surface morphology, X-ray Photoelectron Spectroscopy for chemical bonding, Energy-dispersive X-ray Spectrometry for chemical analyses and X-ray diffraction for crystallinity. The ferroelectric phenomena were confirmed using capacitance-voltage measurements. The integrated physical/chemical features are attempted towards energy-oriented applications applicable to next-generation high-efficiency power generation systems.

• The Korean Journal of Ceramics
• /
• 제3권4호
• /
• pp.249-252
• /
• 1997

Highly oriented ZnO thin films were fabricated by dip-coating technique using zinc acetate 2-methoxyethanol 2-aminoethanol solution as starting materials, and effects of substrates on the film's orientation were investigated. Product films were obtained by prefiring at 300, 400, 500 and 550℃ for 10 min, followed by final heat-treatment at the same temperatures as prefiring for 1h. c-axis oriented films on glass substrates were prepared by heat treatment of prefiring films at 300-550℃, while films on alumina showed polycrystalline structure. Films with c-axis orientation exhibited lower specific resistivities than those of polycrystalline films with partial crack and pore.