• 청정기술
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• 제7권1호
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• pp.65-74
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• 2001

본 연구는 디젤엔진에서 배출되는 NOx환원용 촉매로서 산화반응에서 우수한 활성을 나타내고 있는 페롭스카이트상의 $LaCoO_3$을 sol-gel 공정을 이용하여 촉매코팅용액을 제조한 후, 이를 기존의 dip-coating방법보다 코팅시간, 코팅량, NO-CO 산화 환원 반응에 있어서 경제적이고 효율적인 modified dip-coating방법을 이용하여 촉매코팅필터를 제조하고 이를 후처리장치에 부착함으로써 디젤엔진에서 배출되는 배가스를 효과적으로 제거시키고자 한다. 실험결과, modified dip-coating방법이 기존의 dip-coating방법에 비해서 코팅에 소요되는 용액량이 8.3배 코팅시간 83.3배 단축되었으며, 코팅량은 2~3배정도 커지고, NO-CO 산화 환원 반응성도 1.1~1.8배 가량 증가하였다. 그리고 코팅점도는 $0.006202kg{\cdot}m/sec$을 이용하여 코팅횟수 2회, 코팅량은 88.56mg/g에서 우수한 반응을 보였다. 또한 세라믹 필터의 셀수에 있어서는 200 CPSI가 적절함을 확인할 수 있다.

• Korean Membrane Journal
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• 제7권1호
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• pp.19-27
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• 2005

PP hollow fiber membrane was hydrophilized by EVOH dip coating followed by low temperature plasma treatment and UV irradiation. EVOH coating attained high water flux without any prewetting but its stability did not guaranteed at high water permeation rate. At high water permeation rate, water flux declined gradually due to swelling and delamination of the EVOH coating layer causing pore blocking effect. However, plasma treatment reduces the swelling, which suppress delamination of the EVOH coating layer from PP support result in relieving the flux decline. Also, UV irradiation helped the crosslinking of the EVOH coating layer to enhance the performance at low water permeation rate. FT-IR and ESCA analyses reveal that EVOH dip coating performed homogeneously through not only membrane surface but also matrix. Thermogram of EVOH film modified plasma treatment and W irradiation show that crosslinking density of EVOH layer increased. Chemical modification by plasma treatment and UV irradiation stabilized the hydrophilic coating layer to increase the critical flux of the submerged membrane.

• 한국결정성장학회지
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• 제8권2호
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• pp.292-298
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• 1998

출발원료로 ferric nitrate, ethylene glycol, acethyl acetone 혼합용액을 사용하여 dip-coating된 ${\alpha}-Fe_2O_3$ 막을 제조하였다. coating을 위한 혼합용액의 시간 경과에 따른 용액내의 가교(polymerization) 효과를 관찰하기 위해서 적외선 분광기(FT-IR)를 사용하였고, 막 형성시 유기물 분해 및 결정화 시작온도를 확인하기 위하여 FT-IR, XRD, DSC 등을 이용하여 분석을 행하였다. 또한 AFM과 SEM을 통하여 각 조건에서 제조된 막의 표면상태 및 두께 변화에 대하여 관찰되었다.

• KSBB Journal
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• 제18권2호
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• pp.107-110
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• 2003

스텐트 재질인 stainless steel 표면에 모델 약물인 rose bengal을 포함한 생분해성 고분자 PLGA, PHB, MCL-PHA를 코팅하여 약물방출 특성을 조사하였다. PLGA의 농도가 낮을수록, rose bengal의 농도가 높을수록, dip-coating 시간이 길수록 약물방출이 증가하였으며, PHB > PLGA > MCL-PHA의 순서로 약물이 빨리 방출되었다. 이는 생분해성 고분자의 농도 및 종류, 약물의 농도, dip-coating 시간 등을 변화시켜 약물방출을 조절할 수 있음을 나타낸다.

• 한국의류산업학회지
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• 제22권3호
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• pp.386-398
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• 2020

This study compared dip-coating and in situ polymerization methods for the development of nanofiber-based E-textile using polypyrrole. Nanofiber webs were fabricated by electrospinning an aqueous poly (vinyl alcohol) (PVA) solution. Subsequently, the PVA nanofiber web underwent thermal treatment to improve water resistance. Dip-coating and in situ polymerization methods were used to deposit polypyrrole on the surfaces of the nanofiber web. An FE-SEM analysis was also conducted to examine specimen surface characteristics along with EDS and FT-IR that analyzed the chemical bonding between polypyrrole and specimens. The line resistance and sheet resistance of the treated specimens were measured. Finally, an electrocardiogram (ECG) was measured with textile sensors made of the polypyrrole-deposited PVA nanofiber webs. The polypyrrole-deposited PVA nanofiber webs fabricated by dip-coating dissolved in the dip-coating solution and indicated damage to the nanofibers. However, in the case of in situ polymerization, polypyrrole nanoparticles were deposited on the surface and inter-web structure of the PVA nanofiber web. The resistance measurements indicated that polypyrrole-deposited PVA nanofiber webs fabricated by in situ polymerization with an average sheet resistance of 5.3 k(Ω/□). Polypyrrole-deposited PVA nanofiber webs fabricated by dip-coating showed an average sheet resistance of 57.3 k(Ω/□). Polypyrrole-deposited PVA nanofibers fabricated by in situ polymerization showed a lower line and sheet resistance; in addition, they detected the electrical activity of the heart during ECG measurements. The electrodes made from polypyrrole-deposited PVA nanofiber webs by in situ polymerization showed the best performance for sensing ECG signals among the evaluated specimens.

• 한국진공학회지
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• 제18권4호
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• pp.254-258
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• 2009

순방향 전압에서 안정적인 전류 흐름을 가지고 낮은 turn-on 전압으로 구동하는 이리듐 합성물 기반의 인광 고분자 발광 다이오드를 제작하였다. Poly(N-vinylcabazole)와 tris(2-phenylpyridine)iridium 재료를 포함하는 유기 발광층은 $10{\mu}m$/s 와 $20{\mu}m$m/s의 저속도 dip-coating으로 만들었다. 제안한 방법으로 형성된 유기 발광 다이오드는 100 cd/$m^2$의 기준 휘도에서 각각 5.8 V와 6.7 V로 구동이 되었지만, 발광층을 스핀코팅으로 제작된 소자는 다소 높은 전압인 9.1 V를 기록하였다. 본 연구는 대면적, 용액 공정 기반의 고효율 특성을 요구하는 유기 발광 소자에서 발광층의 새로운 박막 형성기술로 이용될 수 있다.

• Corrosion Science and Technology
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• 제9권4호
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• pp.143-146
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• 2010

For the issue of flaking of the hot-dip galvanizing coating during drawing, the microcosmic characteristics of the coatings have been analyzed and experiments have been done to investigate the influence of coating thickness, Al content and steel substrate strength on its flaking-resistance. The results show that the fact of flaking is that the coating partially flaked off at the position far away from interface of steel substrate and coating, and not entirely flaked off from steel substrate because of poor adhesion. The flaking-resistance of coating decreases with the increasing of coating thickness and steel substrate strength, and increases with the increasing of Al content in coating at the same experimental conditions.

• 한국세라믹학회지
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• 제34권7호
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• pp.774-780
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• 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%.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.191-191
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• 2003

가시광선영역에서 높은 광학적 투명도를 갖는 n-type 반도체인 ZnO 박막은 넓은 범위에서 응용되고 있다. 현재 ZnO 박막의 특성 향상을 위하여 여러 원소(Al, Ga)의 도핑을 시도하고 있다. 특히 Al-doped ZnO 박막은 sol-gel dip coating에 의해서도 높은 전기전도도와 투과율로 활발히 연구되고 있다 본 논문에서는 여러 도핑농도를 갖는 Al-doped ZnO 박막이 sol-gel dip coating법에 의해 준비되었다. Al-doped ZnO 박막은 zinc acetate [Zn($CH_3$COO$_2$)ㆍ2$H_2O$] powder 와 여러 도핑농도를 갖는 aluminum nitrate (Al(NO$_3$)$_3$ㆍ9$H_2O$) powder를 알코올에 용해하여 $H_2O$, Ethylene glycol, Ethylene diamine 등을 첨가하여 제조하였다 XRD와 SEM (Scanning electron microscope)이 막의 상형성 분석을 위해 이용되었으며, 가시광선 영역 투과율(UV/VIS spectrophotometer)과 표면전기저항(four point probe)이 주요 특성으로 분석되었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.215-222
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• 2007

Coating of Hot-dip galvannealed steel consists of various Fe-Zn intermetallic compounds. Since the coating is hard and there for is very brittle, the surface of steel sheet is easy to be ruptured during second manufacturing processing. This is called as powdering. In addition, forming equipment might be polluted with debris by powdering. Therefore, various research have been carried out to prohibit powdering fur improving the quality of GA steel. This paper carried out finite element analysis combined with damage model which simulate the failure of local layer of hot-dip galvannealed steel surface during v-bending test. Since the mechanical property of intermetallic compound was unknown exactly, we used the properties calculated from measurements. The specimen was divided into substrate, coating layer and interface layer. Local failure at coating layer or interface layer was simulated when elemental strain reached a prescribed strain.