• Title/Summary/Keyword: Sol-gel coating method

Search Result 396, Processing Time 0.04 seconds

Comparison of Tribological Characteristics of ZnO Coatings Prepared by Sputtering and Sol-gel Methods

  • Lin, Li-Yu;Kim, Dae-Eun
    • KSTLE International Journal
    • /
    • v.10 no.1_2
    • /
    • pp.23-26
    • /
    • 2009
  • In this work the tribological characteristics were compared between ZnO coatings on glass substrate prepared by sputtering and sol-gel methods. In order to assess the effects of processing method on the tribological characteristics, the friction and wear properties of the coatings were measured by using a reciprocating type of micro-tribotester. The sputtered ZnO coatings were prepared on a glass substrate at room temperature, $150^{\circ}$, and $300^{\circ}$. The ZnO coatings prepared by sol-gel method were heat-treated in air atmosphere at $550^{\circ}$ for one hour. The crystal structure and surface morphology of the coatings were measured by X-ray diffraction (XRD) and Atomic Force Microscope (AFM), respectively. The experimental results showed that overall the sputtered coatings exhibited better friction and wear properties than coatings prepared by sol-gel method. The sputtered coating grown at room temperature had a relatively low friction coefficient of 0.14 and superior wear resistance compared with the other coatings. Nevertheless, sol-gel method of coating ZnO on glass is beneficial for economical coating of a large surface area.

A comparative study of physical properties of $TiO_2$ thin films according to a coating method on orthodontic wires and brackets (교정용 와이어 및 브라켓에 이산화티탄 광촉매 코팅 시 코팅방법에 따른 비교연구)

  • Koh, Eun-Hee;Cho, Jin-Hyoung
    • The korean journal of orthodontics
    • /
    • v.36 no.6
    • /
    • pp.451-464
    • /
    • 2006
  • The purpose of this study was to search for an appropriate method of coating $TiO_2$ on orthodontic appliances. $TiO_2$ thin films were deposited on orthodontic wires and brackets using sol-gel, CVD (Chemical Vapor Deposition) and PE-CVD (Plasma Enhanced-CVD) methods. The roughness of $TiO_2$-coated surfaces was investigated via scanning electron microscope (SEM) and adhesive strength of $TiO_2$ thin films was measured by adhesive tape pull test. Methylene blue degradation test was carried out to evaluate the photocatalytic activity of $TiO_2$ and the corrosion resistance of $TiO_2$ thin films against fluoride solution was also analyzed by observing the surfaces of $TiO_2$-coated wires and brackets via SEM after immersion in sodium fluoride solution. Through the comparison of properties and photocatalytic activity of $TiO_2$ thin films according to the coating methods, the following results were obtained. Smoother surfaces of $TiO_2$ thin films were generated by CVD or PE-CVD methods than through the sol-gel method or the control. Adhesive strength of the $TiO_2$ thin films was highest in PE-CVD and gradually became lower in the order of CVD, then the sol-gel method. Photocatalytic activity of $TiO_2$ thin films on methylene blue was the highest in PE-CVD and gradually became lower in the order of CVD, then the sol-gel method. Corrosion resistance of $TiO_2$ thin films against fluoride solution was stronger in CVD and PE-CVD methods than in the sol-gel method. The results of this study suggest that the CVD or PE-CVD methods is more appropriate than the sol-gel method for $TiO_2$ coating on orthodontic wires and brackets.

Preparation and Characterization of Porous Low Reflective Coating Films for $SiO_2.ZrO_2$ System by Sol-Gel Dip-Coating Method (졸-겔 침지법에 의한 $SiO_2.ZrO_2$계 다공질 저반사 코팅막 제조 및 특성)

  • 김상진;한상목;신대용;김경남
    • Journal of the Korean Ceramic Society
    • /
    • v.34 no.7
    • /
    • pp.774-780
    • /
    • 1997
  • Porous low reflective coating films of SiO2.ZrO2 system were prepared from the mixed alkoxide solutions of Zr(O-nC3H7)4 and partially prehydrolyzed TEOS by the sol-gel method using the dip-coating technique. In the case of 90SiO2.10ZrO2 porous coating films with HCl and H2O content was 0.3 mole and 4 mole, 378 m2/g of the specific surface area, 0.254 cm3/g of total pore volume, 30-50$\AA$ of average pore diameter. The transmittance of 90SiO2.10ZrO2 porous coated films was 95.38% at the wavelength of 550 nm, compared with the parent glass, the transmittance was increased with 4.38%.

  • PDF

Photochromic Properties of Spiropyran in Hard Coating Films Made by Sol-Gel Method (Sol-Gel 하드 코팅 막에서의 Spiropyran의 광 변색 특성)

  • Jeong, Sang Hyeok;Cho, Kyung In;Park, Jeong Yong;Song, Ki Chang
    • Korean Chemical Engineering Research
    • /
    • v.46 no.2
    • /
    • pp.310-315
    • /
    • 2008
  • Organic-inorganic hybrid solutions were made using glycidoxypropyl trimethoxysilane (GPTMS) and vinyltriethoxysilane (VTES) as starting materials by sol-gel method. Photochromic coating solutions were prepared by mixing the solution of photochromic dye (spiropyran) dissolved in ethylacetate with the organic-inorganic hybrid solutions. Photochromic films were prepared on polycarbonate sheets by spin coating and cured for 2 h at $100^{\circ}C$. The resulting films exhibited a reversible color change upon irradiation with UV light from transparent to blue. The color-fading speed and pencil hardness of the coating films increased with increasing the GPTMS content in the coating solutions.

Coloration of Glasses with Squarylium Dye by Sol-Gel Process (Sol-Gel법을 이용한 Squarylium색소의 유리착색)

  • 김성훈;한선경;송경헌;임용진
    • Textile Coloration and Finishing
    • /
    • v.6 no.1
    • /
    • pp.49-53
    • /
    • 1994
  • The transparent coloration of glasses has been successfully achieved by coated glass surface with squarylium dye by the sol-gel colored coating method. Treatment of sol-gel colored coating layer with HCI(g) greatly decreases the absorbance at λ$_{max}$, that increases exposure to $NH_{3}$(g) and the reversible color-colorless responce was extremely rapid.d.

  • PDF

Comparision of Immobilized TiO2 Catalyst for Water Purification (정수처리용 TiO2 고정화 촉매 비교)

  • Jeon, En Ju;Kang, Sung Hwan;Kim, Byung Ug;Rim, Jay Myung
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.13 no.3
    • /
    • pp.101-106
    • /
    • 1999
  • This research aims to compare immobilized catalysts prepared by various methods and determine suitable $TiO_2$ catalyst for water purification. Sol-gel method by Anderson and powder coation method by Tanaka ate famous in the methods to immobilize catalyst. Therefore, the $TiO_2$ catalyst for this research was prepared by sol-gel method and powder coating method. Its structure was tested by X-ray diffractometer (XRD), Scanning electron microseope (SEM). Durability of a catalyst-support couple in an solution was investigated. too. Experimental results were summarized as following; i) Optimum ratio of Ti : $H_2O$ : $H^+$ to obtain stable sol was 1 : 10 : 0.1 and the XRD patterns of $TiO_2$ film immobilized by sol-gel method which were fired at $700^{\circ}C$ showed that the catalyst had an anatase structure. ii) The particle size of $TiO_2$ prepared by sol-gel method was less than $5{\mu}$, but it was observed that coated side was not unifiom. iii) Sol-gel method was very effective to obtain $TiO_2$ catalyst of thin film, but spreadability and durability of a catalyst-support couple in a solution were than $TiO_2$ film immobilized by powder coating method. iv) The particle size of $TiO_2$ immobilized by powder coating method was a little larger than it prepared by sol-gel method, but spreadability and uniformity of $TiO_2$ film and durability of a catalyst-support couple in a solution were better than it immobilized by sol-gel method.

  • PDF

Preparation of Barium Ferrite Thin Film by Sol-Gel Method (졸겔법을 이용한 바륨페라이트 박막 제조)

  • 변태봉;조원덕;김태옥
    • Journal of the Korean Ceramic Society
    • /
    • v.34 no.1
    • /
    • pp.37-44
    • /
    • 1997
  • Barium ferrite thin films on the thermal oxidized Si substrate were prepared by using sol-gel method (dip coating) from the sol of composition ratio of 5.25, designated by mole ratio 2Fe/Ba. The gelation process was largely divided into 4 step, and the sol prepared by reaction for 90 minutes at 8$0^{\circ}C$ was the suit-able for coating. Needle shaped particles formed on the coating layer were placed parallel to substrate and the inclination was increased with film thickness. The easy-direction of magnetization of needle shaped par-ticles was long-axis direction.

  • PDF

Preparation of Hard Coating Solutions using Colloidal Silica and Glycidoxypropyl Trimethoxysilane by the Sol-Gel Method (Sol-Gel 법에 의해 Colloidal Silica와 Glycidoxypropyl Trimethoxysilane으로 부터 하드코팅 용액의 제조)

  • Kim, Dae Hyun;Song, Ki Chang;Chung, Jae Shik;Lee, Bum Suk
    • Korean Chemical Engineering Research
    • /
    • v.45 no.5
    • /
    • pp.442-447
    • /
    • 2007
  • In order to improve the surface hardness of transparent plastic films, organic-inorganic hybrid coating solutions were synthesized by the sol-gel method. The coating solutions were prepared by adding GPTMS (glycidoxypropyl trimethoxysilane) to a colloidal silica (12 nm) suspension. PC(polycarbonate) substrates were dipped into the coating solutions and dried at room temperature for 10 min before being cured at $80^{\circ}C$ for 30 min. The effect of the solution pH and GPTMS content was investigated on the properties of coating films. The pencil hardness and adhesion to substrates of the coating films, prepared at acidic condition (pH 4), showed better properties than those at neutral or basic conditions. Also, the pencil hardness and adhesion to substrates of the coating films increased with increasing GPTMS content.

Additive Coating of BaTiO3 Powder using Sol Coating Method I - Development of Coating Process by BaTiO3 Sol (졸 코팅 법을 이용한 BaTiO3 분체의 첨가제 코팅 I - BaTiO3 졸 코팅 공정 연구)

  • 신효순
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.17 no.9
    • /
    • pp.953-959
    • /
    • 2004
  • BaTiO$_3$ powder has been applied in so much electronic ceramics. Therefore, as recent, the method to add or coat additive will be needed BaTiO$_3$ powder. As a kind of the method, the coating of BaTiO$_3$ powder was considered. In this study, during BaTiO$_3$ powder was coated by BaTiO$_3$ sol, gelation path was experimented. Standard coating condition was set for homogeneous coating. The phase of the gel was deferent by gelation path. It was confirmed the amorphous gel was made in BaTiO$_3$ phase easily at low temperature. In the amorphous gel, particle growth was shown at 900$^{\circ}C$, because crystallization temperature was low. The optimal ratio of sol and powder was at 10 vol% for the homogeneous coating.