• 한국세라믹학회지
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• 제56권6호
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• pp.601-605
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• 2019

This work reports the preparation of ceramic hybrid films with illite-polyethylene composites analyzed as a function of concentration of added illite in polyethylene. The enhancement of oxygen and water-vapor transmission rate of illite-polyethylene film was evaluated to determine its influence on the freshness in fruit packaging. Particle size of illite materials was controlled in the range of 1~10 ㎛ and then mixed with LDPE to form the masterbatch. Ceramic hybrid films were prepared through a blown film making process. To determine the dispersity and abundancy of illite materials in the polyethylene matrix, various characterizations of illite-PE hybrid masterbatch and films were performed using SEM, TGA, and FT-IR. The oxygen and water-vapor transmission rate of illite-polyethylene film was found to be two times higher than that of LDPE film.

• 동아시아식생활학회지
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• 제23권4호
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• pp.461-469
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• 2013

This research is performed to investigate the changes in the physicochemical properties and microbial growths of seasoned anchovies with various packaging materials (PET/CPP : polyethylene terephthalate/cast polypropylene, PET/EVOH : polyethylene terephthalate/ethylene-vinyl alcohol, PET/AL/LDPE: polyethylene terephthalate/aluminum/low density polyethylene), which are stored at various temperatures (25, 35, $45^{\circ}C$) for 60 days. Generally, it is being observed that changes in physicochemical properties (i.e., moisture content, color, brown intensity, TBA value, TMA, VBN etc) of seasoned anchovies are significant when stored at higher temperatures. Particularly, the packaging materials are found to influence substantially on the physicochemical properties of seasoned anchovies. With packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e., PET/CPP), the changes in physicochemical properties of seasoned anchovies are significant, while being low with low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). In addition, results of microbial growths in seasoned anchovies show that significant increases in total aerobic bacteria counts (about 100-fold after 60 day of storage) are observed in samples with packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e, PET/CPP), while with only small increases for samples of low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). Based on the changes in the physicochemical properties and results of microbial growths, it is being concluded that PET/EVOH film is suitable for the packaging of seasoned anchovies.

• Carbon letters
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• 제14권4호
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• pp.247-250
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• 2013

In this study, we present a facile method of fabricating graphene oxide (GO) films on the surface of polyimide (PI) via layer-by-layer (LBL) assembly of charged GO. The positively charged amino-phenyl functionalized GO (APGO) is alternatively complexed with the negatively charged GO through an electrostatic LBL assembly process. Furthermore, we investigated the water vapor transmission rate and oxygen transmission rate of the prepared (reduced GO $[rGO]/rAPGO)_{10}$ deposited PI film (rGO/rAPGO/PI) and pure PI film. The water vapor transmission rate of the GO and APGO-coated PI composite film was increased due to the intrinsically hydrophilic property of the charged composite films. However, the oxygen transmission rate was decreased from 220 to 78 $cm^3/m^2{\cdot}day{\cdot}atm$, due to the barrier effect of the graphene films on the PI surface. Since the proposed method allows for large-scale production of graphene films, it is considered to have potential for utilization in various applications.

• Composites Research
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• 제34권1호
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• pp.63-69
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• 2021

일체형 방열 및 기체 차단 재료 개발을 위하여 신규 고분자를 합성하고 판상형 육방정 질화 붕소(hBN) 필러를 포함하는 복합소재를 제조하였다. 복합소재는 필러의 크기 및 함량에 따라 열전도도 및 산소투과도 조절이 가능하였다. 복합소재는 최대 28.0 W·m-1·K-1의 높은 열전도도를 지녔으며 필러 미포함 샘플 대비 산소투과도는 62% 감소하였다. 열전도도 및 기체투과도 실험 측정값과 모델 예측값 비교를 통해 복합소재 내 필러의 종횡비를 계산하였다. 이러한 결과를 토대로 높은 열전도도 및 낮은 기체투과도는 필러 간 효과적인 네트워크 형성 때문이며 이는 복합소재 제조 시 전단 응력 극대화가 가능한 신규 수지의 특성으로부터 유래된것으로 사료된다. 또한, 열전도도로부터 계산된 필러 종횡비와 산소 투과도로부터 계산된 필러 종횡비 값이 서로 다름을 확인하였고 이에 관련하여 복합소재에서 열 전달 및 기체 투과 메커니즘에 대하여 고찰하였다. 본 연구에서 개발된 높은 열전도도 및 낮은 산소투과도를 갖는 고분자 복합소재는 전자 제품의 일체형 방열 및 산화 방지 재료로 사용 될 수 있다.

• 한국포장학회지
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• 제24권1호
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• pp.13-16
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• 2018

Powdered infant formula is susceptible to oxidation in the presence of oxygen. Even though the product is usually packaged in nitrogen atmosphere, the oxygen ingress through the package layer may occur in case of flexible pouches and affects the oxidation of the product. $O_2$ barrier of the package is thus important variable to protect the product from oxidative deterioration. $O_2$ barrier property was investigated for aluminum-laminated small pillow packs of $3.5{\times}17.5cm$. Storage temperature and combination of primary and secondary packages were evaluated as variables affecting the barrier for conditions of empty pouch flushed with nitrogen. Apparent oxygen transmission rate of the primary package exposed to air was $2.32{\times}10^{-3}mL\;(STP)\;atm^{-1}\;d^{-1}$ at $30^{\circ}C$ and its temperature dependence could be explained by activation energy of $28.5kJ\;mol^{-1}$ in Arrhenius relationship. The additional secondary package of nylon/PE film containing 20 primary packages was ineffective in modulating package $O_2$ transmission and was only marginally helpful when combined with oxygen scavenger. The same was true in suppressing the product oxidation when the primary package was filled with 14 g of the formula.

• 한국식품영양과학회지
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• 제33권7호
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• pp.1224-1229
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• 2004

PHB/chitosan 필름의 수분 투과도는 PHB 필름께서 280.25 g/m$^2$ㆍ24 hr로 가장 높았고 chitosan의 함량이 증파할수록 수분 투과도는 낮아지는 경향을 보였다. PEG가 첨가된 PHB/chitosan 필름에서도 PHB-P 필름의 수분 투과도가 294.5 g/m$^2$ㆍ24 hr로 가장 높았고, chitosan의 함량이 증가할수록 수분 투과도는 낮아졌다. 산소 투과도의 경우 PHB 필름이 0.026${\times}$$10^{-10}$$cm^3$(STP) cm/$cm^2$ㆍsecㆍcmHg로 가장 높았으며 chitosan의 첨가 비율이 증가할수록 산소 투과도는 낮아졌다. 또한 가소제인 PEG가 첨가되지 않은 필름이 PEG가 첨가된 필름보다 산소 투과도가 더 낮았다. 유지 투과도에서는 PHB와 PHB-P를 제외한 필름들이 24시간동안 유지론 통과시키지 않아 유지 차단성이 우수한 것으로 나타났다. 필름의 생분해도 측정시 필름을 첨가하지 않은 대조군에 비해 필름이 첨가된 실험군의 산소 소모량이 높아 필름이 생분해되고 있음을 확인할 수 있었으며 필름의 PHB의 비율이 높을수록 분해도가 높은 것으로 나타났다.

• 한국세라믹학회지
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• 제41권5호
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• pp.364-369
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• 2004

The barrier and optical properties of AlO$_{x}$ thin films on polycarbonate deposited by Reactive Ion Beam Sputtering (RIBS) were investigated at different oxygen partial pressure. We measured the deposition rate of AlO$_{x}$ thin films. As the oxygen partial pres-sure increased, the deposition rate increased then decreased. The changes of deposition rate are associated with the properties of deposited films. The properties of deposited AlO$_{x}$ thin films were studied using X-ray Photoelectron Spectroscopy (XPS), Scan-ning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). Optimum deposition parameters were found for fabricat-ing aluminum oxide thin films with high optical transparency for visible light and low Oxygen Transmission Rate (OTR). The optical transmittance of AlO$_{x}$ thin film deposited on polycarbonate (PC) showed the same value of bare PC.bare PC.

• 한국환경과학회지
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• 제26권1호
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• pp.1-10
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• 2017

In this study, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/graphene oxide (GO) nanocomposite films containing various content of GO were prepared using solution casting method. The effect of GO content on Young's modulus and dispersion of GO in PHBV matrix was investigated. Also, the thermomechanical properties, oxygen transmission rates and hydrolytic degradation of PHBV/GO nanocomposite films were studied. The addition of GO into PHBV improves the Young's modulus and decreases thermal expansion coefficient. The improvement can be mainly attributed to good dispersion of GO and interfacial interactions between PHBV and GO. Furthermore, PHBV/GO nanocomposite films show good oxygen barrier properties. PHBV/GO nanocomposites show lower hydrolytic degradation rates with increasing content of GO.

• 한국임상보건과학회지
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• 제5권4호
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• pp.1021-1025
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• 2017

Purpose: Changes in corneal thickness after wearing hydrogel lens and silicone-hydrogel lens with different oxygen transmission rates wew syudied. Methods: Experiments were performed on 11 subjects(22 eyes). corneal thickness was measured after wearing contact lenses for 8 hours. Corneal thickness was measured using ORB Scan II(ver. 3.14) Results: In the results of the corneal thickness measurement by direction, in the case of the hydrogel-tor lens, the center thickness was $33.63{\mu}m$, the nasal was $34.29{\mu}m$, the temporal was $27.17{\mu}m$, the inferior was $27.17{\mu}m$, the superior was $18.90{\mu}m$, and change rates were 6.28%, 5.71%, 5.40%, 4.75% and 3.09%, respectively. In the results of the corneal thickness measurement by diameter, in the case of the hydrogel-tor lens, the center was $33.63{\mu}m$, the mid-peripheral was $28.19{\mu}m$, the peripheral was $24.18{\mu}m$, and change rates were 6.28%, 4.76%, and 3.79%, respectively. Conclusions: The hydrogel lenses with relatively low oxygen transmission rates resulted in a significant increase in thickness over the entire cornea compared to silicon-hydrogel lenses with high oxygen transmission rates.

• 전자공학회논문지D
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• 제36D권4호
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• pp.48-56
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• 1999

본 논문에서는 초기 산소 농도가 고에너지 이온 주입시 결정 격자 손상에 의해 발생하는 산소 축적(pileup) 현상 및 주입된 불순물의 확산에 미치는 영향을 실험적으로 고찰하였다. 초기 산소 농도가 11.5, 15.5 ppma인 p-type (100)실리콘 웨이퍼에 \sup 11\B\sup +\ \sup 31\P\sup +\ 이온을 각각 1.2 MeV, 2.2 MeV 의 에너지로 1×10\sup 15\cm\sup 2\ 주입하고, 700℃(20시간)+1000℃(10시간)의 2단계 열처리를 거치 후 주입된 불순물 및 산소 농도의 분포를 이차이온질량분석기 (Secondary Ion Mass Spectrometry, SIMS)로 관찰하였으며 잔류 2차 결함의 분포는 투과전자현미경(Transmission Electron Microscopy, TEM)으로 관찰하였다. SIMS 측정 결과 산소의 축적이 {{{{ { R}_{ } }}}}\sub p\(projected range) 부근에서 관찰되었으며 열처리 후에도 상당한 양의 2차 결합 띠가 {{{{ { R}_{ } }}}}\sub p\부근에서 관찰되는 것으로 보아 2차 결함에 의해 산소가 포획되었음을 알 수 있다. 또한 붕소와 인의 확산은 웨이퍼의 초기 산소 농도가 클수록 벌크 방향으로의 확산이 증대되는 현상을 볼 수 있었다.