• 멤브레인
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• 제25권5호
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• pp.440-446
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• 2015

다공성 PE (polyethylene) 정밀여과막 지지체 위에 이온교환고분자 물질을 염석법 및 가압법(phase separated and pressurization, PSP)으로 코팅하여 저압용 나노여과막을 제조하였다. 제조한 나노여과막의 코팅유무는 SEM 사진을 통하여 확인하였으며 코팅물질, 코팅시간, 이온세기에 따라 NaCl 100 ppm에서 투과도와 배제율을 측정하였다. PEI와 PSSA_MA의 농도를 동일하게 10,000 ppm으로 하고, 3 atm의 코팅압력을 주어 코팅한 결과, PEI의 투과도는 91.2 LMH, 제거율은 64.6% 이었으며 PSSA_MA의 투과도는 122.7 LMH, 제거율은 38.1%의 결과를 얻을 수 있었다. 본 연구로부터 염석법과 가압법을 통해 복합막 제조가 가능하다는 결론을 얻을 수 있었다.

• 한국태양에너지학회 논문집
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• 제33권3호
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• pp.27-35
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• 2013

One of the most important factors that have a large influence on performance of the solar water heater system is performance of the solar collector, more detailedly, coating technology on the surface of the solar collector, which can provide high solar absorptance and low emittance. The core of the coating technology is to coat solar selective surfaces. In this study, various performance experiments are carried out using $Cr_2(SO_4)_3{\cdot}15H_2O$ coating technology. Here, IGBT(Insulated Gate Bipolar Transistor) of 5000A-15V was used as the surface processing rectifier which can stably output power and also can control voltage and current. The plating solution mainly contains black chrome$^{+3}$ concentration, H-y Conductivity, N-u Complex, NF Additive and NC-2 Wetter. Before applying the black chrome coating on the copper plate, optimal conditions are provided by using various preprocessing methods such as removal of fat, activation, electrolytic polishing, nickel strike, copper sulfate plating and bright neckel plating, and then the automatic continuous coating experiment are performed according to plating time and cathode current density. In the experiment, after the removal of fat, chemical polishing, nickel strike and activation processes as the preprocessing methods, the black chrome coating was performed in a plate solution temperature of $28^{\circ}C$ and a cathode current density of $18A/cm^2$ for 90 seconds. The thickness of chrome and nickel on the coated plate is $0.389{\mu}m$, $159{\mu}m$ respectively. As a result of the coating experiment, it showed the most excellent performance having a high solar absorptance of 98% and a low emittance of $5{\pm}1%$ when the black chrome surface had a thickness of $0.398{\mu}m$.

• Corrosion Science and Technology
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• 제8권4호
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• pp.157-161
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• 2009

The corrosion resistance of reinforcing bar was studied to endure the marine environment during shipment. The red rust on the surface did not damage the adherence in the concrete structures, especially in highly alkaline environment, but made the consumer doubt of the quality. The passivation process by alkalization of the quenching water in the tempcore process failed to endure the long shipping period. The ceramic coating by sol-gel process improved the corrosion resistance without damaging the mechanical properties and adherence between concrete and reinfiorcing bar. Optimal concentration of the coating solution and coating temperature were tested. No additional energy was necessary for the coating process by spraying during cooling process, resulting simplified process and low cost. Salt spray test, cyclic corrosion test and atmospheric test were employed to confirm the resistance. The corrosion rates were presented by rating number and polarization resistance. The coating layer was examined by FIB, XRD and SEM etc.

• 한국표면공학회지
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• 제49권2호
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• pp.172-177
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• 2016

In this paper, various electrochemical experiments were conducted in seawater solution to evaluate corrosion damage behavior of arc thermal sprayed Inconel 625 coating on SS400 steel in marine environment. As a result, corrosion damages of thermal sprayed Inconel 625 coating preferentially occurred at the defect area, and they were observed as a form of pitting corrosion in the galvanostatic experiments. In Tafel analysis, corrosion current density of Inconel 625 coating was relatively high due to influence of interconnected pores and Cr oxides in the thermal spray coating layer. On the other hand, the result of the potential measurement, thermal sprayed Inconel 625 coating should need the post-treatment which can compensate the defects like pores and cracks because Inconel 625 coating presented a higher potential of about 290 mV than that of the SS400 steel.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.83-84
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• 2020

In present study, we have deposited the Zinc coating using arc thermal spray and plasma arc spray processes onto the steel substrate and durability of the deposited coating was evaluated. The bond adhesion result shows that plasma arc sprayed Zn coating exhibited higher in its value compared to arc thermal spray. SEM shows that Zn coating deposited by plasma arc process is more compact, less porous and adherent compare to arc spray process. The corrosion resistance properties are evaluated in artificial ocean water solution with exposure periods. EIS results show that total impedance at 0.01 Hz of plasma arc sprayed coating is higher than arc thermal spray owing to the compact and less porous morphology. It is concluded that plasma arc sprayed Zn coating is better than arc thermal spray process.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.525-535
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• 2017

내열성이 우수하며, 태양광 모듈의 유리 표면에 방담성(antifogging) 및 방오성(antifouling)을 동시에 부여하여 효율을 향상시키기 위한 친수성 코팅액을 제조하기 위해 초친수성과 우수한 방담효과를 나타내는 Tween 20과 데카플루오로부탄과 폴리에틸렌글리콜 성분으로 구성된 불소계면활성제 수용액에 방오성 부여를 위하여 나노실리카를 분산하였다. 고온 처리에서 나노실리카의 함량에 따른 방담 효과는 모든 코팅액이 우수하였으나, 방오 효과는 나노실리카의 함량이 6 wt%일 때부터 나타났다. 불소계면활성제의 함량이 증가할수록 초기 접촉각이 증가하며 방담 효과도 500회 wiping까지 잘 유지되었다. 방오 효과 역시 불소계면활성제의 함량에 상관없이 우수하여 불소계면활성제의 적절한 첨가량은 0.1 wt%이상 이면 충분하였다. AFM 결과로부터 불소계면활성제가 0.1 wt%에서 0.3 wt%가 첨가된 경우 코팅 표면의 프랙탈구조가 확실히 나타나 방오성 향상에 기여하였다. 코팅된 유리의 투과도는 불소계면활성제가 0.1 wt% 첨가된 TL-1의 경우가 가장 높았으며 더 많은 양의 불소계면활성제를 첨가할 경우 오히려 투과도 향상은 미미하였다. 이러한 결과는 앞의 AFM 결과에서 나타난 표면 조도가 높으며 프랙탈구조 형성도 잘 일어난 TL-1 코팅액의 결과와 잘 일치하는 것이다.

• 동력기계공학회지
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• 제20권5호
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• pp.20-28
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• 2016

This study has developed an organic/inorganic hybrid solution by addition of $SiO_2$ polysilicate and Melamine to the urethane. The three types of cold rolled steel were evaluated a corrosion resistance properties by using these solutions. The urethane solution(U) and the urethane solution with $SiO_2$ polysilicate($US_7$) were generate a lot of corrosion. The urethane solution with $SiO_2$ polysilicate and melamine($US_7M_3$) was excellent in corrosion resistance, regardless of the steel type. In addition, corrosion resistance has been shown to depend on the tensile strength. The appearance of coating by U and $US_7$ solution is bumpy surface, and were a lot of fine defects. $US_7M_3$ solution is made a sophisticated molecular cross-linking structure inside the coating, it was a slick surface. Other characteristics are exhibited the excellent property for all solutions.

• 펄프종이기술
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• 제35권5호
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• pp.17-25
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• 2003

The influence of base paper properties and fiber type on coating penetration was studied in terms of characterization of coating holdout using two types of hand sheets as the base paper which were prepared from thermomechanical pulp (TMP) and hardwood bleached kraft pulp(KP) sized internally with alkyl ketene dimmer (AKD). Laboratory rod draw down coater was used for surface sizing and coating application. Characterization of coating penetration was done by measuring the roughness of the backside of coating layer. The backside of the coating was exposed by dissolving the fibers in a solution of cupriethylenedimine (CEO). Data show that internal sizing of base paper is effective and surface sizing is more effective to prevent coating penetration. Comparing between the two types of base papers, backside roughness of coating layer of TMP sheet is much larger and sizing is more effective to reduce coating penetration than those of KP sheet. From the result of water absorption and sizing degree after surface sizing, it seems that internal sizing slows down molecular diffusion much more than capillary penetration, but surface sizing reduces the capillary penetration. Furthermore, predominant mechanism of water into paper of TMP sheet seems to be capillary penetration, but it is molecular diffusion in the case of KP sheet.

• 한국표면공학회지
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• 제48권4호
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• pp.169-173
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• 2015

$CuInSe_2$ thin films which have been widely used for thin solar cells as a light absorber were prepared by hydrazine solution processing, and their microstructural properties were investigated. Hydrazine $CuInSe_2$ precursor solutions were prepared by dissolving $Cu_2S$, S, $In_2Se_3$ and Se powder in hydrazine solvent. Multilayer $CuInSe_2$ chalcopyrite phase thin films were prepared by repeating spin-coating process using the precursor solution. Unfortunately, the presence of the interfaces between each $CuInSe_2$ layer formed by multi-layer coating impeded grain growth across the interface. Here, by doing simple interface engineering to solve the limited grain growth issue, the large grained (${\sim}1{\mu}m$) $CuInSe_2$ thin films were obtained.

• 폴리머
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• 제27권6호
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• pp.555-561
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• 2003

미세전자기계 시스템에 사용되는 실리콘 기판의 표면 특성 조절을 위하여 옥타데실트리클로로실란 (OTS)을 실리콘에 자기조립 단분자층 (SAMs)으로 형성시켜, 코팅 조건 및 코팅 용액 조성에 따른 표면특성 변화를 살펴보았다. OTS와의 솔-젤 반응을 위하여 실리콘 표면을 sulfuric peroxide mixture (SPM) 용액으로 처리한 결과, 실리콘 표면에 -OH기가 형성되어 친수성이 증가됨을 알 수 있었으며 상온에서 황산의 비가 85%인 SPM 용액에서 솔-젤 반응을 위한 최적의 산화막이 형성됨을 알 수 있었다. SPM 처리에 의하여 발현된 실리콘 표면의 -OH기는 솔-젤 반응에 의하여 OTS의 -CI와 반응하여 Si-O 화학결합을 형성하며 이에 따라 표면은 소수성으로 변화됨을 확인할 수 있었다 이 때 코팅 온도 및 시간 그리고 용액의 조성은 솔-젤 반응에 영향을 미쳐 SAMs표면의 소수성을 조절하는 인자로 작용하였다.