• Composites Research
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• 제19권3호
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• pp.23-28
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• 2006

탄소나노튜브로 강화된 구리기지 적층 나노 복합재료를 제작하였고, 마이크로 인장 시험기를 이용하여 기계적 물성을 평가하였다. 탄소나노튜브 층이 강화제로 사용된 샌드위치 형태의 적층 구조는 탄소나노튜브의 선택적인 딥코팅 방법과 전해도금 방법을 이용하여 제작되었다. 본 연구에서 정립한 공정을 사용하여 제작된 나노 복합재료는 구리 기지만을 사용한 재료에 비해 기계적 물성이 향상되었다. 이는 평면내 방향으로 균일하게 분산된 탄소나노튜브에 의해 하중 분산 용량이 증가되었기 때문이며, 두께 방향으로 적층된 구리 기지를 탄소나노튜브 층이 상호 지지하여 인장물성이 강화됨을 확인하였다. 기능적 재료의 제작에 있어 적층 구조는 다양한 분야에 적용될 수 있으며, 본 연구에서는 입자강화복합재료 강화제의 적용 가능성을 확인하였다.

• 한국포장학회지
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• 제30권1호
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• pp.73-83
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• 2024

In this study, environmental evaluation of high barrier coated paper (coating layer/paper) packaging is conducted in comparison with conventional aluminum laminated (PET/VMPET/LLDPE) plastic packaging. The target product for this packaging is a KF94 mask, which requires a high barrier of water and oxygen to maintain the filtration ability of the mask filter. The functional unit of this study is 10,000 mask packaging materials based on a material capable of blocking oxygen (<1 g/m²day) and moisture (<3 g/m²day) for the preservation of KF94 masks. In order to understand the results easily, paper-based mask packaging system divided into 6 stages (pulp, pulping & paper making, calendaring & coating, printing, packing and waste management), while plastic-based mask packaging consists of 5 stages (material production, processing, printing, packing, waste management) In case of paper-based mask packaging, most contributing stage is calendaring & coating, resulting from heat and electricity production. On the other hand, plastic-based mask packaging is contributed more than 30% by material production, specifically due to linear low density polyethylene and purified terephthalic acid production. The comparison results show that global warming potential of paper-based mask packaging has 32% lower than that of plastic-based mask packaging. Most of other impact indicators revealed in similar trend.

• 접착 및 계면
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• 제2권2호
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• pp.1-10
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• 2001

Epoxy molding compound (EMC)에 사용되는 실리카를 13.56 MHz 플라즈마 중합 장치를 이용하여 코팅하였으며, 코팅시간, 플라즈마전압, 내부압력을 변화시키면서 코팅조건을 최적화하였다. 플라즈마 중합 코팅용 단량체로는 1.3-diaminopropane, allylamine, pyrrole, 1,2-epoxy-5-hexene, allylmercaptan 및 allylalcohol을 사용하였으며, 코팅된 실리카의 접착성은 굴곡강도 측정으로 분석하였다. 또한 열팽창 계수 (CTE) 및 수분 흡습률 변화를 측정하였으며, 파괴 단면을 SEM으로 분석하여 접착 특성을 규명하고자 하였다. 플라즈마 중합 코팅된 실리카와 에폭시 수지간의 접착기구를 규명하기 위하여 플라즈마 고분자 코팅을 FT-IR로 분석하였으며, DSC를 이용하여 코팅된 실리카와 에폭시 수지간의 반응성도 고찰하였다. 1,3-diaminopropane과 allylamine으로 코팅된 실리카를 함유하는 EMC는 비교시편에 비하여 높은 굴곡강도, 낮은 CTE 및 낮은 흡습율을 보였으며, SEM 분석 결과 100% cohesive failure 거동을 나타내었다. 이러한 결과는 고분자 코팅내의 아민 반응기와 에폭시 수지간의 화학적 결합에 의한 것으로 판단되며, FT-IR 및 DSC 분석결과와 부합된다.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3045-3050
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• 2011

The synthesis of copolymers containing thiophene and benzimidazole unit by Stille polymerization is reported. The polymers with many unsubstituted thiophene units in the backbone have been reported to show low solubility, which has been a problem for spin-coating for the device fabrication. In dihexyl-2H-benzimidazole, the sulfur at 2-position of BT unit was replaced with dialkyl substituted carbon, while keeping the 1,2-quinoid form, to improve the solubility of the polymers. The PL emission spectra of the PHBIT1, PHBIT2 and PHBIT3 in chloroform solutions show maximum peaks at 500~561 nm. In thin films, maximum peaks of the PHBITs appeared at 529, 562 and 569 nm, respectively. The EL emission maxima of the PHBIT1 and PHBIT2 appear at around 588 and 576 nm, respectively. The current density and maximum luminescence of the LED with the configuration of ITO/PEDOT/ PHBIT2/Ca/Al are 552 mA/$cm^2$ and 46 cd/$m^2$, respectively.

• KSBB Journal
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• 제24권6호
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• pp.515-520
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• 2009

This study presented facile method of cell patterning using fabricated PDMS patterns on polyelectrolyte coated surface. This basic principle is the fabrication of functional surface presenting two orthogonal surfaces such as cell adhesive and repellent properties. Cell adhesive surface was firstly fabricated with simple coating of polyelectrolyte multilayer. And then, the desired patterns of PDMS for the prevention of nonspecific binding of cells were transferred onto the previously formed thin film of polyelectrolyte multilayer. Thus, we could prepare novel functional surface simultaneously containing PDMS and polyelectrolyte region. As expected, the PDMS regions showed effective prevention of nonspecific binding of cell and the other region, exposed polyelectrolyte area, provided cell adhesive environment. The height of formed PDMS structure was about 100 nm. Based on this method, cell patterning can be successfully obtained with various pattern shapes and sizes. Therefore, we expect that this simple method will be useful platform technology for the development of cell chip, cell based assay system, and biochip.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.7.1-7.1
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• 2011

Nanoporous templates have been widely used for the development of new functional nanostructured materials suitable for electronics, optics, magnetism, and energy storage materials. We have prepared nanoporous templates by using thin films of mixtures of polystyrene-block-poly (methyl methacrylate) (PS-b-PMMA) and PMMA homopolymers. These templates have cylindrical nanoholes spanning the entire thickness of the film. Some applications of nanoporous templates are introduced: a) anti-reflective coating, b) the preparation of conducting polymer nanowires of poly (pyrrole), poly (3,4-ethylenedioxy-thiopene) onto a glass coated with indium-tin-oxide, and c) the separation membranes for biomaterials. We found that when the pore fraction of nanoholes in the film was ~0.68, almost zero reflectance at a specific wavelength, which can be changed with film thickness, was achieved at visible wavelengths Furthermore, ultra high density array of conducting nanowires was successfully prepared onto various substrates including flexible polymer. Due to highly alignment of polymer chain along the nanowire direction, the conductivity was much increased. Furthermore, these nanoporous films were found to be very effective for the separation of human Rhinovirus type 14 (HRV 14), major pathogen of a common cold in humans, from the buffer solution. We also found that when the pore size was effectively controlled down to 6 nm, a single file diffusion was observed.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2367-2370
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• 2014

"Cat's eye"-shaped $[^{57}Co]CoO@SiO_2$ core-shell nanostructure was prepared by the reverse microemulsion method combined with radioisotope technique to investigate a potential imaging agent for a single photon emission computed tomography (SPECT) in nuclear medicine. The core cobalt oxide nanorods were obtained by thermal decomposition of $Co-(oleate)_2$ precursor from radio isotope Co-57 containing cobalt chloride and sodium oleate. The $SiO_2$ coating on the surface of the core cobalt oxide nanorods was produced by hydrolysis and a condensation reaction of tetraethylorthosilicate (TEOS) in the water phase of the reverse microemulsion system. In vivo test, micro SPECT image was acquired with nude mice after 30 min of intravenous injection of $[^{57}Co]CoO@SiO_2$ core-shell nanostructure.

• 한국염색가공학회지
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• 제29권3호
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• pp.148-154
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• 2017

Many researches have been made on the processing technology of Poly(ethylene terephthalate) (PET), which is widely used for clothing and non-clothing applications. In this study, we coated PET filaments with m-aramid resin to improve heat resistance and antimicrobial properties. In order to enhance adhesion between PET and m-aramid polymer, the adhesive polymer was coated on the PET filaments using a winding speed of 100m/min and then treated with m-aramid. Scanning electron microscopy was used to analyze the surface of the adhesive polymer and m-aramid treated PET filament. The change of initial degradation temperature according to treatment was confirmed by thermogravimetric analysis. Antimicrobial activity analysis using bacterial reduction method showed that PET filament treated with adhesive polymer and m-aramid had an increased antibacterial effect compared to untreated PET filament.

• Corrosion Science and Technology
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• 제18권5호
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• pp.155-167
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• 2019

In this study, two novel Schiff base compounds including (3-(4-Chlorophenyl isoxazole-5-yl) methanol and (3-(2,4 dichlorophenol isoxazole-5-yl) methanol as corrosion inhibitors for mild steel in 1 M hydrochloric acid solution were investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and density functional theory (DFT) computations. The results showed that the corrosion inhibition efficiency (IE) is remarkably enhanced with the growing concentration of the Schiff base inhibitors. The results from Tafel polarization and EIS methods showed that IE decreases with gradual increments of temperature. This process can be attributed to the displacement of the adsorption/desorption balance and hence to the diminution of the level of a surface coating. Also, the adsorption of two inhibitors over mild steel followed the Langmuir adsorption isotherm. Too, the results of the scanning electron microscope (SEM) images showed that the Schiff base inhibitors form an excellent protective film over mild steel and verified the results by electrochemical techniques. Additionally, the results from the experimental and those from DFT computations are in excellent accordance.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1870-1875
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• 2020

Probiotics are often infused into functional foods or encapsulated in a supplement form to maintain a healthy balance between the gut microbiota and their host. Because there are milk-based functional foods such as yogurt and cheese on the market, it has been suggested that milk-based probiotics could be incorporated into skim milk proteins in a liquid capsule. Skim milk is mainly composed of casein and whey protein, which create a strong natural barrier and can be used to encapsulate probiotics. In this study, we compared the encapsulated probiotics prepared with milk-based concentrated cell mixtures using commercial probiotics. Probiotic capsules were emulsified with skim milk proteins using vegetable oil to form a double coating layer. The product was heat-stable when tested using a rheometer. The survival rate of the milk-based probiotic cells in the lower gastric environment with bile was significantly higher than commercial probiotics. Thus, milk-encapsulated probiotics exhibited greater efficacy in the host than other types of probiotics, suggesting that the former could be more viable with a longer shelf life under harsh conditions than other form of probiotics. Our findings suggested that, compared with other types of probiotics, milk-based probiotics may be a better choice for producers and consumers.