• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.42-45
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• 2001

The high permittivity are applied to DRAM and FRAM. (Ba,Sr)$TiO_3$ (EST) thin films were prepared by Sol-Gel method. BST solution was made and spin-coated on $Pt/SiO_2/Si$ substrate at 4000 [rpm] for 10 seconds in a time coating. Coated specimens were dried at $90[^{\circ}C]$ for 5 minutes. Coating process was repeated from 3 times to 5 times and then sintered at $750[^{\circ}C]$ for 30 minutes. Each specimen was analyzed structure and electrical characteristics. Thickness of BST ceramics thin films are about 2600-2800[$\AA$] in 3 times. Dielectric constant of thin films was little decreased at 1[KHz]~1[MHz]. Dielectric constant and loss to frequency were 250 and 0.02 in BST3. The property of leakage current was stable When the applied voltage was 0~3[V] Leakage current was $10^{9}\sim10^{11}$[A] at 0~3[V].

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.112-117
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• 2008

1:1로 몰 비가 조절된 glycidoxypropyl trimethoxysilane(GPTMS)과 methyl triethoxysilane(MTES)을 출발물질로 하여 sol-gel법에 의해 유-무기 혼성 용액을 제조하였다. 이 용액에 spiropyran계 광 변색 염료를 ethylacetate(EA)에 용해시킨 용액을 혼합하여 광 변색 코팅 용액을 제조하였다. 그 후 기재인 polycarbonate 시트에 스핀 코팅 시키고 $100^{\circ}C$에서 2 h 동안 열 경화 시켜 광 변색 코팅 막을 제조하였다. 코팅 막은 UV 광을 조사함에 의해 가역적인 색변화를 보여주었다. 이때 코팅 막의 소색속도는 코팅 용액 중의 EA의 첨가량이 증가됨에 따라 증가하였다.

• 한국세라믹학회지
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• 제28권11호
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• pp.859-864
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• 1991

High quality lead titanate thin films were fabricated by spin coating on a silicon substrate. The resulting dried gel layers were uniform in thickness through 2$\times$2 $\textrm{cm}^2$ area, and polycrystalline perovskite structures developed almost crack free with a heat treatment above 50$0^{\circ}C$ in films with thickness above 360 nm. Metastable pyrochlore structures were observed in films with thickness of 160 nm when heat treated at 500 and $600^{\circ}C$, but these structure did not appear in films with thickness of 360 nm. The thickness dependence in crystal structure of films was studied. by varying the substrate condition and analyzing the interface between the film and substrate. In native oxide films on silicon stbstrates, amorphous dried gel layers were heterogeneously nucleated. Metastable cubic pyrochlore structure could be crystallized in amorphous native oxide.

• 한국표면공학회지
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• 제50권5호
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• pp.366-372
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• 2017

Plasma electrolytic oxidation(PEO) has attracted attention as a surface treatment which has high wear resistance and corrosion resistance. PEO is generally considered as cost-effective, environmentally friendly and superior in terms of coating performance. Most of studies about the PEO processes have been applied to light metals such as Al and Mg. Because the strength of Al and Mg is weaker than that of steel, there is a limit to the application. In this study, PEO process was used to form oxide coatings on Hot dipped aluminized(HDA) steel and the characteristics of the coating film according to the PEO current density were studied. The morphology was observed by SEM and component was analyzed by using EDS. The corrosion behaviors of PEO coating films were estimated by exposing salt spray test at 5 wt.% NaCl solution and measuring polarization curves in deaerated 3 wt.% NaCl solution. With the increase of PEO process current density, the pore size of the coating surface and the thickness of coating increased. It was confirmed that no Fe component was present on the coating surface. PEO coating films obviously showed good corrosion resistance compared with HDA. It is considered that the PEO coating acts as a barrier to protect the base material from external factors causing corrosion.

• Corrosion Science and Technology
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• 제15권2호
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• pp.78-83
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• 2016

The e-coating to inhibit induced corrosion can deposit a coating not only on the exterior surface but also on the inside of whole metallic components of body-in-white (BIW). But it is difficult to deposit paint films on the inside area because metallic components are multi layered. It may cause shortness of e-coating thickness. The only way to properly verify e-coating thickness is by performing the use of tear-down prototypes. When paint films' thickness is inadequate, a structural modification on each metallic component is needed. Verification of the thickness improvement for a structural modification requires much manual effort and leads to increasing development time. Recently, the simulation technology has been developed to predict the e-coating thickness in e-coating field. By applying the simulation to BIW, improvement in paint thickness quality and shortening of development period are expected. The paper explains a validated solution that allows simulating the effect of design changes to the e-coating thickness and current density, thereby delivering results within a time frame of a few days.

• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.40-43
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• 2016

Transparent color coating films were fabricated on a glass substrate by using sol-gel hybrid binder and organic dye. Sol-gel hybrid binder coating film fabricated with PTMS of 0.03 mole showed a very high pencil hardness of 9 H. As the withdrawal speed increased from 1.0 mm/s to 5.0 mm/sec, The yellowness ($b^*$) of coating glass also gradually increased. The transmittance of yellow color coating glass was 82.6% and the haze of coating glass was 0.35%. Red and blue color coating glasses also showed the high transmittance of 62.4% and 80.6% respectively. The surface hardness of color coating films was 6 H.

• 한국세라믹학회지
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• 제49권1호
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• pp.95-99
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• 2012

Silicon carbide ceramics are used for oxidation resistive coating films due to their excellent properties like high strength, good oxidation resistance, and good abrasion resistance, but they have poor formability and are prepared by vapor process which is complicated, costly, and sometimes hazardous. In this study, preparation of silicon carbide coating film by liquid process using polymer precursor was attempted. Coating film was prepared by dip coating on substrate followed by heat treatment in argon at $1200^{\circ}C$. By changing the dipping speed, the thickness was controlled. The effects of plasticizer, binder, or fiber addition on suppression of crack generation in the polymer and ceramic films were examined. It was found that fiber additives was effective for suppressing crack generation.

• 한국산학기술학회논문지
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• 제11권5호
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• pp.1773-1777
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• 2010

광경화(UV-curing)에 의한 PVC 바닥상재 코팅기술은 PVC 바닥상재 질의 개선을 위하여 사용되는 것이다. 본 연구에서 사용한 폴리우레탄 아크릴레이트 수지는 반응성 모노머, 광개시제, 그 외 첨가제를 배합하여 제조하였고, 올리고머는 상용화된 지방족 우레탄 아크릴레이트를 사용하였다. 제조한 코팅액을 바코팅(bar-coating) 방법으로 PVC 바닥상재에 코팅한 후 광경화법을 이용하여 상재표면에 코팅층을 형성하였다. 코팅에 사용된 코팅액은 FTIR로 측정하여 특성을 확인하였으며, PVC 상재 표면에 형성된 코팅층의 물성은 광택과 부착력으로 평가하였다. 코팅층의 물성은 코팅조성과 공정조건에 영향을 받았다.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.463-466
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• 2008

We report a method to increase the surface area of the titania films used as the anodes of dye-sensitized solar cells (DSSCs) by applying additional titania-coating. The modification was achieved by spin-coating a coating solution that contained a surfactant with a titania source onto the titania electrodes, followed by calcination. Previous similar attempts without a surfactant all reported decreased surface areas. We fabricated DSSCs by using the modified titania films as the anode and measured their performances. The increased surface area increased the amount of adsorbed dyes, which resulted in increased current densities. At the same time, the titania-coating increased both the open-circuit voltage and the current density by reducing the charge-recombination rates of the injected electrons, similar to the results of literatures. Therefore, our method shows an additional mechanism to increase the current density of DSSCs in addition to the other mechanisms of surface modifications with titania-coatings.

• Korean Chemical Engineering Research
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• 제59권2호
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• pp.165-173
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• 2021

눈부심 방지(Anti-glare, AG) 코팅 필름은 액정 디스플레이, LED 조명, 터치 패널 등 다양한 디스플레이 분야에 적용되고 있다. 본 연구에서는 UV 경화형 코팅 용액 내에 충전제로써 마이크로미터 크기의 실리카 입자를 첨가하여 눈부심 방지 효과를 부여하고자 하였다. 이 과정 중 실리카 입자의 크기, 함유량, 교반 시간, 다른 크기의 실리카 입자의 혼합 비율이 코팅 도막의 haze 값과 가시광선 투과도에 미치는 영향을 조사하였다. 그 결과 실리카 입자의 크기가 클수록, 또한 실리카 입자의 함유량이 증가할수록 haze 값은 증가하나, 가시광선 투과도는 감소하였다. 반면 교반 시간은 haze 값과 투과도에 큰 영향을 주지 못하였다. 또한 큰 크기의 실리카의 혼합 비율이 증가할수록 haze 값은 증가하나, 이와 반대로 가시광선 투과도는 감소하는 것을 확인할 수 있었다.