• 폴리머
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• 제27권3호
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• pp.195-200
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• 2003

알지네이트는 곁사슬에 강한 음이온을 가지고 있어 전기장 하에서 구동 특성을 발현할 수 있다. 본 연구에서는 가교제로 CaCl$_2$를 사용하여 가교 알지네이트 필름을 제조하였고, 제조된 필름의 열적 특성, 기계적 특성 및 전기적 구동 특성을 열중량 분석, 인장 강도 실험 및 전기응답 실험을 통하여 조사하였다. 가교제의 농도가 증가함에 따라 필름의 초기 분해 온도와 인장 강도가 증가하였다. 또한 팽윤비는 사슬 내 자유부피와 정전기적 반발력에 기인하여 가교제 농도의 감소와 pH가 증가함에 따라 증가하였다. 저기 자극에 의하여 알지네이트 필름은 유연한 물리적 거동을 발현하였다. 전기장에서 전압, 이온 강도 및 저해질 용액의 종류에 따라서 필름의 응답 속도 띤 거동에 영향을 주었다. 가교제의 농도가 5 wt%일 때 가장 좋은 굽힘 거동과 반복 회복성을 보였으며, NaCl과 KCl 전해질 용액의 이온 강도가 0.1 M일 때 가장 높은 전기 반응성을 나타냈다. 또한 전압이 증가됨에 따라 전하의 이동이 활발해지고 따라서 굽힘 거동이 증가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.161-164
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• 2001

Transmuted impurity atoms formed in neutron-irradiated ZnO thin films were theoretically identified first and then experimentally confirmed by Photoluminescence (PL). ZnO thin films grown by plasma-assisted molecular beam epitaxy were irradiated by neutron beam at room temperature. Among eight isotropes naturely exiting in ZnO films, only $^{64}Zn$, $^{68}Zn$, $^{70}Zn$ and $^{18}O$ were expected to transmute into $^{65}Cu$, $^{69}Ga$, $^{71}Ga$ and $^{19}F$, respectively. The concentrations of these transmuted atoms were estimated by considering natural abundance, neutron fluence, and neutron cross section. The neutron-irradiated ZnO thin films were characterized by PL. In the PL spectra of these ZnO thin film, the Cu-related PL peaks were seen, but the Ga- or F-associated PL peaks were absent. This observation demonstrates the existence of $^{65}Cu$ in the ZnO. In this paper, emission mechanism of Cu impurities wil1 be described and the reason for the absence of the Ga- or F-associated PL peaks will be discussed.

• 한국포장학회지
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• 제20권1호
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• pp.7-15
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• 2014

Agar-based composite films were prepared with variety of food processing and agricultural processing waste materials in order to screen natural lingo-cellulosic resources for the value-added utilization of the under-utilized materials. The effect of these waste materials (10 wt% based on agar) on mechanical properties, moisture content (MC), water vapor permeability (WVP), water absorption behavior of biocomposite films were investigated. Biocomposite films prepared with various fibers resulted in significant increase or decrease in color and percent transmittance. The MC, WVP, and surface hydrophobicity of biocomposite films increased significantly by incorporation of fibers, while the water uptake ratio and solubility of the film decreased. SEM images of biocomposite film showed better adhesion between the fiber and agar polymer. Among the tested cellulosic waste materials, rice wine waste, onion and garlic fibers were promising for the value-added utilization as a reinforcing material for the preparation of biocomposite food packaging films.

• 한국응용과학기술학회지
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• 제16권1호
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• pp.25-31
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• 1999

Algin is known as biodegradable natural polymer from marine plants. PVA/Algin blend films were prepared by solution blending method for the purpose of useful biodegradable polymer. Characteristics properties of PVA/Algin blend films such as DSC, Elongation, Tensile strength and Morphological change by SEM were determined. Tensile strength and Elongation were rapidly reduced as increasing the blend ratio of Algin. PVA/Algin blend films were found that phase separation was occured as more than 25wt% increasing the blend ratio of Algin. Blend films were observed to be less partially compatibility than 10wt% increasing the blend ratio of Algin by DSC, mechanical properties and SEM. Also, PVA/Algin blend films at the laboratory soil test(Pot Test) were completely degraded in months with four kinds of soils by microorganisms.

• Journal of Ceramic Processing Research
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• 제19권6호
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• pp.479-482
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• 2018

Polystyrene superstructure films show faint rainbow color, and this low color saturation limits its wide application. In this paper, polystyrene superstructure films with single bright blue color were prepared by vertical deposition self-assembly method using polystyrene microspheres with average diameter of $310{\pm}10nm$ as raw material. Polystyrene superstructure films were modified by adding nano-carbon powder, and effect of the amount of nano-carbon powde on color performance was studied. The results showed that without addition of nano-carbon powder, the superstructure films showed a faint rainbow color, while with addition of nano-carbon power, the superstructure films exhibited a single bright blue under the same natural light source. Changing the amount of nano-carbon powder addition could adjust color saturation of the film. With increasing the amount of nano-carbon powder addition from 0.008 wt% to 0.01 wt%, color saturation of the superstructure film increased gradually. Further increasing the amount of nano-carbon powder addition to 0.011wt%, color saturation of the superstructure film didn't increase anymore and tended to get dark.

• Journal of Dairy Science and Biotechnology
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• 제41권4호
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• pp.219-229
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• 2023

Consumer demand for products with health benefits and natural ingredients is significant for the expansion of functional foods. Edible films and coatings are an excellent way to diversify the market for functional foods and as substitutes for the prevailing packaging and products. Incorporation of whey protein (WP) and its active ingredients into edible films and coatings is a promising technique that can be applied to various food products. Numerous combinations can be used on an industrial scale depending on the purpose, product, nature of the film, type of active ingredient, and type of inclusions. In this review, we describe several characteristics of edible WP films and coatings used as novel packaging materials. WP-based packaging can play a beneficial role in sustainability because of the option of recycling materials rather than incinerating, as in synthetic laminates, because of the use of natural byproducts from the food industry as raw materials. However, cost-effectiveness is a driving force against industrial setbacks in current and future WP processing developments. The industrial application of this new technology depends on further scientific research aimed at identifying the mechanism of film formation to improve the performance of both the process and product. Furthermore, research such as consumer studies and long-term toxicity assessments are required to obtain significant market shares.

• 대한전기학회논문지
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• 제44권10호
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• pp.1311-1316
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• 1995

The electrical properties of the Langmuir-Blodgett (LB) films layered with arachidic acid were studied at the room temperature. The sample was formed with 2 different structure ; One was Al/LB/Al and the other was Au/LB/Au. The precise structure of Al/LB/Al was considered as Al/Al$_{2}$O$_{3}$/LB/Al, because the natural oxide layer was formed on surface of lower Al electrode. The electrical conductivity of Al/Al$_{2}$O$_{3}$/LB/Al structure was determined the value of 3.5 * 10$^{-14}$ S/cm from the measurement of current-voltage (I-V) characteristics. The sample with the structure of Au/LB/Au was made to eliminate the influence of oxide layer in the electrical properties of the LB films. The short circuit current was observed in this sample from the I-V characteristics. To verify the reason of short circuit current generation, copper decoration method was employed to the 15 layers of LB films deposited on the Al and Au electrode each. The defects were shown on the films deposited with Au electrode. This results means that the defects on the LB films which layered with the Au electrode were contributed to the short circuit current. Several films (15, 31, 51, 71L) were deposited on the Au electrode and measured the size of defects with the copper decoration method. The size of defects becomes smaller as the film layer was increased. We conclude that the existence of defects affects the short circuit current generation.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2514-2516
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• 2007

• 통합자연과학논문집
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• 제7권3호
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• pp.183-187
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• 2014

Lead zirconate titanate (PZT) is significant material in electrical and optical devices for their ferroelectric, piezoelectric and dielectric properties. In this research, PZT films were fabricated by reactive RF co-sputtering method using Pb, Zr, and Ti targets. From XPS study, lead, zirconium, and titanium are successfully deposited on Si(100) substrate. Thickness of PZT films was measured with a surface profiler and the thickness was decreased as the oxygen gas ratio increased in the sputter gas.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.97-100
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• 1990

Diamond thin films were synthesized by the MPECVD (Microwave Enhanced Chemical Deposition) using the mixture of the hydrogen and organic compounds($CH_3COCH_3$, $CH_3OH$). In X-ray Diffraction, the d values of all the deposits on the Si substrates with the experimental conditions coincide with those of natural diamond in POD (Powder Diffraction Data). The changes of the morphology of all the deposits were examined by SEM. The amount of amorphous carbon or graphite in the diamond films were increased as the acetone concentration was increased. The morphology of the diamond particles can be changed from ball-like to euhedral by adding the small amount of the methanol in the reaction gases of the high acetone concentration.