• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.363-363
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• 2010

The high capillarity of a plastic fiber network having superhydrophilic Si-DLC coating is studied. Although the superhydrophilic surface maximize wetting ability on the flat surface, there remains a requirement for the more wettable surface for various applications such as air-filters or liquid-filters. In this research, the PET non-woven fabric surface was realized by superhydrophilic coating. PTE non-woven fabric network was chosen due to its micro-pore structure, cheap price, and productivity. Superhydrophobic fiber network was prepared with a coating of oxgyen plasma treated Si-DLC films using plasma-enhanced chemical vapor deposition (PECVD). We first fabricated superhydrophilic fabric structure by using a polyethylene terephthalate (PET) non-woven fabric (NWF) coated with a nanostructured films of the Si-incorporated diamond-like carbon (Si-DLC) followed by the plasma dry etching with oxygen. The Si-DLC with oxygen plasma etching becomes a superhydrophilic and the Si-DLC coating have several advantages of easy coating procedure at room temperature, strong mechanical performance, and long-lasting property in superhydrophilicity. It was found that the superhydrophobic fiber network shows better wicking ability through micro-pores and enables water to have much faster spreading speed than merely superhydrophilic surface. Here, capillarity on superhydrophilic fabric structure is investigated from the spreading pattern of water flowing on the vertical surface in a gravitational field. As water flows on vertical flat solid surface always fall down in gravitational direction (i.e. gravity dominant flow), while water flows on vertical superhydrophilic fabric surface showed the capillary dominant spreading.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.24.1-24.1
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• 2010

In practical operation, the exposed surfaces may get dirty thus degrade the performance of devices. So the combination of self cleaning and antireflection is very desirable for use in outdoor photovoltaic and displaying devices, self cleaning windows and car windshields. For the purpose of self cleaning, the surface needs to be either superhydrophobic or superhydrophilic. However, in practice AR in the visible region and self cleaning are a pair of competitive properties. To satisfy the requirements for superhydrophobic or superhydrophilic surfaces, high surface roughness is required. But it usually cause severely light scattering. Photo-responsive coatings (TiO2, ZnO etc.) can lead to superhydrophilic. However, the refractive indices are high. Thus for porous structure, controlling pore size in the underwavelength scale to reduce the light scattering is very crucial for highly transparent and self cleaning antireflection coating. Herein, we demonstrate a simple method to make high performance broadband antireflection layer on the glass surface, by "carving" the surface by hot alkali solution. Etched glass has superhydrophilic surface. By chemical modification, it turns to superhydrophobic. Enhanced transparency (up to 97%) in a broad wavelength range was obtained by short time etching. Also antifogging effect has been demonstrated, which may offer advantage for devices working at high humidity environment or underwater. Compositional dependence of the properties was observed by comparing three different commercially available glasses.

• 한국결정학회지
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• 제12권3호
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• pp.177-181
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• 2001

TiO₂박막의 초친수성 특성을 열처리에 따른 박막의 결정구조 변화와 연관지어 연구하였다. 박막은 Sol-Gel법을 이용하여 실리콘 (100)웨이퍼 위에 제조하였다. 1차 소결후, 500℃에서 후열처리한 시편은 anatase 상을, 1000℃에서 열처리한 시편은 rutile 상을 가지며 그 중판 온도인 750℃에서 열처리한 경우는 anatase와 rutile상이 혼재 되어 있다. 이 후열 처리한 시편들은 UV를조사하지 않아도 친수성을 보였고, 특히 750℃에서 열처리한 시편은 5°이하의 초친수성을나타내었다. 친수성을 가지는 시편들은 암실처리 중 서서히 퇴화되어 소수성을 띄게되지만, UV를 조사하면 1시간 이내에 급격히 초진수성을 회복하는 우수한 특성을 보였다.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.229-237
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• 2018

Medical silicone tubes are generally used as implants for the treatment of nasolacrimal duct stenosis. However, side effects such as allergic reactions and bacterial infections have been reported following the silicone tube insertion, which cause surgical failure. These drawbacks can be overcome by modifying the silicone tube surface using a functional coating. Here, we report a biocompatible and superhydrophilic surface coating based on a polysaccharide multilayer nanofilm, which can load and release antibacterial and anti-inflammatory agents. The nanofilm is composed of carboxymethylcellulose (CMC) and chitosan (CHI), and fabricated by layer-by-layer (LbL) assembly. The LbL-assembled CMC/CHI multilayer films exhibited superhydrophilic properties, owing to the rough and porous structure obtained by a crosslinking process. The surface coated with the superhydrophilic CMC/CHI multilayer film initially exhibited antibacterial activity by preventing the adhesion of bacteria, followed by further enhanced antibacterial effects upon releasing the loaded antibacterial agent. In addition, inflammatory cytokine assays demonstrated the ability of the coating to deliver anti-inflammatory agents. The versatile nanocoating endows the surface with anti-adhesion and drug-delivery capabilities, with potential applications in the biomedical field. Therefore, we attempted to coat the nanofilm on the surface of an ophthalmic silicone tube to produce a multifunctional tube suitable for patient-specific treatment.

• 한국기계가공학회지
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• 제21권7호
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• pp.77-83
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• 2022

When carbon dioxide in a liquid becomes supersaturated, carbon dioxide gas bubbles are generated in the liquid, and they ascend to the surface as they develop further. At this time, the inner wall of the cup with carbon gas attached is known as the entrapped gas cavity (EGS); once an EGS is established, it does not disappear and will continuously create carbon bubbles. This bubbling phenomenon can be activated or suppressed by changing the properties of the solid surface in contact with the carbonated liquid. In this study, the foaming of carbonated liquid is promoted or suppressed by modifying the wettability of the surface. A micro/nano surface structure is formed on the surface of an aluminum cup to produce a superhydrophilic surface, and a superhydrophobic surface similar to a lotus leaf is synthesized via fluorination. Experiment results show that the amount of carbon dioxide bubble generated differs significantly in the first few seconds depending on the surface, and that the amount of gas generated after it enters the stabilization period is the same regardless of the wettability of the cup surface.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2001년도 임시총회 및 추계학술대회연구발표회(한국결정학회)
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• pp.25-25
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• 2001

• 한국고분자학회지:고분자과학과기술
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• 제22권3호
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• pp.248-255
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• 2011

• 한국정밀공학회지
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• 제29권1호
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• pp.19-24
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• 2012

We demonstrate the desert beetle back mimicking hybrid superhydrophilic/superhydrophobic patterned surface by using the combination method of colloidal lithography and gravure offset printing for nano and micro patterning, respectively. The two methods are cost-effective and industrially available techniques compared to the other nano/micro patterning methods. To verify the water collecting function of the hybrid surface, the water condensation behavior is investigated on the chilled surface in ambient temperature and high humidity. Due to the synergetic effect of drop and film wise condensation, the hybrid superhydrophobic/superhydrophilic surface shows the higher efficiency than one of single wettability surfaces. The work is underway to get the good patterns of hybrid surfaces for water collecting from the dew or fog.

• 한국결정성장학회지
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• 제20권4호
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• pp.168-172
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• 2010

양전하를 갖는 poly(allylamine hydrochloride)(PAH)와 음전하를 갖는 poly(acrylic acid)(PAA) 전해질 폴리머를 사용하여 layer-by-layer(LBL) self-assembly 방법에 의해 초친수 특성을 갖는 박막을 제조하였다. PAH/PAA 박막의 밀착강도를 증가시키기 위하여 glutaraldehyde(GA) 수용액을 이용하여 amine-aldehyde의 화학반응에 따른 박막의 표면구조 변화, 막두께, 투과율, 접촉각, 밀착강도 특성을 측정하였다. PAH와 PAA 용액 침적 사이에 기판을 GA 수용액에 침적함으로써 박막의 두께는 감소하였지만 밀착강도는 2배 이상 증가하였다. 밀착강도의 증가는 PAH 와 GA의 amine-aldehyde의 화학반응에 의한 결과라는 것을 fourier transform infrared(FT-IR) spectroscopy를 사용하여 확인하였다. 제조된 PAH/PAA and PAH/GA/PAA 박막은 물 접촉각 $5^{\circ}$이하의 초친수 박막 특성을 보여주었고, 550 nm 파장에서 91.3% 이상의 높은 투과율을 나타내었다.

• 접착 및 계면
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• 제16권4호
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• pp.152-155
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• 2015

백금은 주조가 쉽고 잘 부식되지 않으며 다양한 화학 반응의 촉매로 사용되는 물질이다. 이러한 다양한 장점 때문에, 배기가스 필터, 부식 방지 전극, 수술 및 생체 이식 재료 등 다양한 분야에서 백금의 활용도가 높다. 그러나, 여느 금속과 마찬가지로 백금 표면은 물에 대한 젖음성이 그다지 크지 않아, 수계 환경에서 표면의 활용성이 좋지 않다. 이에, 본 연구에서는 백금을 매우 간단하면서도 효과적으로 젖음성을 향상시켜 초친수성(superhydrophilic)으로 만들어주는 코팅 방법을 보고하고자 한다. Sodium 3-mercapto-1-propanesulfonic acid 용액을 이용하여 백금 표면을 코팅한 결과, 백금 표면의 물에 대한 접촉 각이 $10^{\circ}$ 이하로 감소하는 것을 확인하였다. 단순 담금 코팅을 통해 만든 sodium 3-mercapto-1-propanesulfonic acid 자가조립 단분자막을 이용해 성공적으로 백금 표면을 초친수성 표면으로 코팅하는데 성공하였다.