• 한국식품과학회지
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• 제47권6호
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• pp.733-737
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• 2015

나노 $TiO_2$ 코팅 필름은 식품 포장재에서 많이 사용하는 PU와 PVB-cellulose 두 가지 바인더에 나노 콜로이달 $TiO_2$를 각각 3%와 5%의 농도로 혼합제조하여 OPP 필름에 코팅하였다. PVB 바인더로 코팅한 필름이 PU 바인더(3%와 5%)보다 불균일하게 필름에 코팅이 되었다. 그러나 청변현상 방지 실험과 광분해 실험에서는 필름 코팅 상태와 상관없이 선도 유지 효과가 나타났다. MB를 사용한 광분해성 효과 측정 실험에서 나노 $TiO_2$의 광촉매 반응으로 인해 초기 30분부터 MB가 분해되는 것을 확인하였고, 콩나물 포장재 내에서 혐기성 호흡으로 발생하는 이취인 acetaldehyde는 나노 $TiO_2$ 코팅 필름이 대조구에 비해 농도가 감소하는 것을 확인하였다. 따라서 개발된 나노 $TiO_2$ 코팅 필름으로 콩나물의 청변 현상과 이취 제거로 인해 콩나물의 보관 수명을 연장할 수 있었다.

• 한국포장학회지
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• 제24권1호
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• pp.1-11
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• 2018

본 연구에서는 수출 가능한 식품포장재로 pro-oxidant($d2w^{(R)}$)함유 rPP/ZnO 나노컴포지트 유연필름을 제조하였고, 이 산화분해 필름의 기계적 특성과 항균기능을 조사하였다. 산화분해필름은 일정조건의 열과 자외선 처리를 거친 후 특성분석으로 FT_IR, SEM, UTM, GPC를 측정하여 물성변화를 관찰하였다. 카보닐지수와 하이드록실지수에서 열과 자외선에 노출율이 많아질수록 수치는 상승하였다. 표면분석에서는 rPP/$d2w^{(R)}$/ZnO나노컴포지트 필름의 경우 표면이미지가 매끈하여 ZnO의 첨가가 고분자의 상용성을 향상시켰고, 열과 자외선차단효과로 분해를 감소시키는 효과로 작용하였다. 항균력시험에서는 그람음성균은 대장균으로 그람양성균은 황색포도상구균으로 항균력을 측정하였다. 결과로는, ZnO는 시험에 사용한 농도에서 3로그 이상의 미생물 감소율을 나타내었다. 그러나 유연 필름용으로는 ZnO의 농도가 높아질수록 투명도가 떨어지므로 사용에 제한이 있었다. rPP/$d2w^{(R)}$/ZnO가 함유한 시편에서 인장강도는 40% 상승하였고, 신율은 30% 감소되었다. ZnO를 첨가한 경우 기계적 물성상승과 열 안전성과 자외선차단성을 나타내었다. 산화분해능은 열 노출 $70^{\circ}C$ 온도에서 480시간 경과한 후, 자외선 조사로 72시간 노출 이후 시점의 분자량은 수평균분자량이 1,294 g/mol, 무게평균분자량이 5,920 g/mol로 분해되는 결과를 얻었다. 이것으로 UAE 5009:2009, ASTM 6954의 기준에 준한 필름을 제조할 수 있었다. 비교시편과 본 연구에서 제조한 산화분해필름의 분자량이 80.7%와 75.6% 감소한 결과를 얻음으로서, 자연 산화분해됨을 확인하였다. 식품포장재로서 안전성분석에서는 국내법 중 식품접촉플라스틱 폴리프로필렌의 기준에 적합하였다.

• 한국산학기술학회논문지
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• 제20권5호
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• pp.363-371
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• 2019

본 연구는 한국 여성 340명을 대상으로 자외선 차단제 유형, 사용 실태에 따른 사용인식이 제품 사용만족도와 재구매에 미치는 영향을 분석하고자 사용인식을 편리성, 유효성, 사용성, 안전성으로 하위요인을 구성하여 설문조사를 이용한 연구를 하였다. 연구 결과, 실내 활동 빈도가 야외활동 보다 높게 나타났고 피부톤 보정을 위해 단순 및 복합 자외선 차단제를 둘 다 사용하는 경우가 많았으며, 단순 자외선 차단제 중 선크림을, 복합 자외선 차단제 중 에어쿠션을 많이 사용하였다. 제품 사용감, 자외선 차단 지수가 구매의 중요한 요인이었고 제품 사용만족도 및 재구매 의사가 높게 나타났지만 30%가 부작용을 경험하였다. 단순 자외선 차단 제품이 복합 자외선 차단 제품보다 안전성, 유효성, 편리성, 사용성, 만족도, 재구매에 대한 인식정도가 모두 높게 나타났고 제품 사용인식 하위요인 중 편리성, 유효성, 사용성, 안전성 순으로 만족도와 재구매에 유의한 정(+)의 영향을 미쳤다. 결론적으로 자외선 차단을 위한 제품 사용 시 단순 자외선 차단 제품에 대한 인식이 더 높았고, 편리성이 만족도 및 재구매에 큰 영향을 미치는 것이 확인되었다.

• Toxicological Research
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• 제21권2호
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• pp.99-105
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• 2005

Photo-mutagenic compounds have been known to alter skin cancer rates by acting as initiators or by affecting subsequent steps in carcinogenesis. The objectives of this study are to investigate the utility of photo-chromosomal aberration (photo-CA) assay for detecting photo-clastogens, and to evaluate its ability to predict rodent photocarcinogenicity. Photo-CA assay was performed with five test substances that demonstrated positive results in photo-carcinogenicity tests: 8-Methoxypsoralen (photoactive substance that forms DNA adducts in the presence of ultraviolet A irradiation), chlorpromazine (an aliphatic phenothiazine an alpha-adrenergic blocking agent), lomefloxacin (an antibiotic in a class of drugs called fluoroquinolones), anthracene (a tricyclic aromatic hydrocarbon a basic substance for production of anthraquinone, dyes, pigments, insecticides, wood preservatives and coating materials) and Retinoic acid (a retinoid compound closely related to vitamin A). For the best discrimination between the test substance-mediated genotoxicity and the undesirable genotoxicity caused by direct DNA absorption, a UV dose-response of the cells in the absence of the test substances was firstly analyzed. All 5 test substances showed a positive outcome in photo-CA assay, indicating that the photo-CA test is very sensitive to the photo-genotoxic effect of UV irradiation. With this limited data-set, an investigation into the predictive value of this photo-CA test for determining the photo-carcinogenicity showed that photo-CA assay has the high ability of a test to predict carcinogenicity. Therefore, the photo-CA test using mammalian cells seems to be a sensitive method to evaluate the photo-carcinogenic potential of new compounds.

• 한국지역사회생활과학회지
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• 제28권1호
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• pp.143-154
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• 2017

This study was conducted to develop fabrics using non-toxic and eco-friendly natural dyes made from curcuma and coffee extract. The natural dyes were applied to non-printed cotton fabrics using the dip dyeing method, and the pattern was hand-printed onto the dyed fabrics to make dyed printed-fabrics. The four types of developed fabric samples were compared to analyze the effects of the dyeing materials and printing on the hygienic properties of curcuma- and coffee-dyed fabrics. The findings were as follows. First, air permeability of both curcuma- and coffee-dyed fabrics was greatly affected by the presence of patterns, although the type of dye did not seem to have an effect. Printing greatly reduced air permeability of the fabric, and coffee-dyed fabric showed greater reduction of dyeing method than curcuma-dyed fabric. Moisture regain also tended to decrease with printing, but the change was much smaller compared to air permeability. Second, increased UV blockage was observed in curcuma- and coffee-dyed fabrics with patterns compared to non-printed fabrics, showing that printing enhanced UV blocking. Third, deodorization rate tended to increase sharply for both curcuma- and coffee-dyed fabrics until 30 minutes and gradually increased thereafter to yield 30% for curcuma and 50% for coffee at 120 minutes, demonstrating higher deodorization of coffee dye. Coffee-dyed fabric showed an antibacterial rate about twice as high as that of curcuma-dyed fabric, and the observed data suggest that curcuma-dyed fabric had an insignificant level of antibiosis. Fourth, printing significantly enhanced wash, sunlight, and compound colorfastness of the two types of dyed fabrics. The effect of printing was most dramatic on sunlight and compound colorfastness, which are aspects in which natural dyed fabrics perform poorly in general. Eventually, the development and application of biologically- and environmentally-friendly fabrics with natural dyes correspond with increased interest towards the wellness and healthy attitudes of modern society.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1567-1573
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• 2020

Ultraviolet (UV) is one of the major factors harmful to skin health. Irradiation with ultraviolet accelerates the decline of skin function, causing the skin to have deep wrinkles, dryness, decreased procollagen production, and degradation of collagen. Novel materials are needed to prevent the aging of the skin by blocking the effects of UV. Safflower seed oil (Charthamus tinctorius L., SSO) contains significantly high levels of unsaturated fatty acids and phytochemicals. SSO has been traditionally used in China, Japan, and Korea to improve skin and hair. Our objective in this study was to determine the effect of SSO and its active compound acacetin on UVB-induced skin photoaging in HaCaT cells and human dermal fibroblasts (HDF). SSO inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) at both protein and mRNA levels in HaCaT cells and HDF. MMP-1 is known to play important roles in collagen degradation and wrinkle formation. Acacetin, a type of flavonoid, is present in SSO. Similar to SSO, acacetin also inhibited UVB-induced MMP-1 protein and mRNA levels in HaCaT cells and HDF. MMP-1 mRNA is primarily regulated by the mitogen-activated kinase (MAPK) signaling pathway. Acacetin regulated the phosphorylation of JNK1/2 and c-jun, but did not inhibit the phosphorylation of ERK1/2, p38 and AKT. Taken together, these results indicate that SSO and its active compound acacetin can prevent UVB-induced MMP-1 expression, which leads to skin photoaging, and may therefore have therapeutic potential as an anti-wrinkle agent to improve skin health.

• 대기
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• 제21권1호
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• pp.123-130
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• 2011

In this study, we have analyzed the radiative characteristics of erythemal ultraviolet-B (EUV-B from 1999 to 2005) over the Korean Peninsula. EUV-B measured at Gangneung, Anmyondo, Mokpo, and Gosan represents the measurements from clean areas and that at Seoul represents from a polluted area. The magnitudes of EUV-B increase in proportion to the latitudinal decrease. Monthly mean variation of EUV-B at noon shows the maximum value of $158.5mWm^{-2}$ in August and the minimum value of $36.4mWm^{-2}$ in December in the clean areas. Seasonal mean diurnal variation of EUV-B shows a peak around noon (12:00 ~ 13:00 hr) and its intensity varies along with a season in order of summer > spring > fall > winter. The maximum value of $56.4mWm^{-2}$ in summer is three times higher than that in winter ($14.3mWm^{-2}$). The value of EUV-B in the polluted area is lower than that in the clean areas, resulting from the effects of the blocking, reflection, and scattering of EUV-B due to high concentrations of PM10. UV-B is an essential element to synthesize vitamin D in human body. 200 IU(International Unite) of vitamin D can be formed by an exposure of 6-10% of body surface area to 0.5 MED(Minimal Erythemal Dose). In order to form vitamin D, the calculated exposure times to EUV-B are 15 min. in spring, 12 min. in summer, 18 min. in fall, and 37 min. in winter for the clean areas and 16, 16, 24, and 37 min. for the polluted area.

• Elastomers and Composites
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• 제44권3호
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• pp.290-298
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• 2009

본 논문에서 Fe-활성탄소 섬유(ACF)/$TiO_2$ 복합체 광촉매를 졸-겔 방법에 의하여 제조하였다. 합성된 광촉매는 UV조사하에서 MB용액의 광분해에 사용되었다. BET 데이터는 Fe와 Ti의 여러 가지 농도를 가지고 처리된 ACF의 표면에서 흡착 특성을 보여준다. SEM 사진에서 보여지는 것처럼, 철 혼합물과 $TiO_2$는 ACF 표면에 활착되어 있음을 나타내었다. X선 분말 회절법으로부터 얻어진 결과는 복합체로부터 FeO+$TiO_2$, Anatase 및 Rutile 구조의 결정상을 나타내었다. 원소분석을 위한 EDX spectra는 Fe와 함께 C, O, Ti의 peak들이 존재함을 나타내었다. MB 분해에 대한 활성은 $TiO_2$의 광분해와 Fe의 photo-Fenton 효과로 인해 전자/hole쌍 반응으로부터 파생된 -OH 라디칼들에 의한 것으로 여겨진다.

• 한국분말재료학회지
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• 제29권3호
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• pp.207-212
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• 2022

Nanosized rutile titanium dioxide (TiO₂) is used in inorganic pigments and cosmetics because of its high whiteness and duality. The high quality of the white pigments depends on their surface coating technique via the solgel process. SiO₂ coatings are required to improve the dispersibility, UV-blocking, and whiteness of TiO₂. Tetraethyl orthosilicate (TEOS) is an important coating precursor owing to its ability to control various thicknesses and densities. In addition, we use Na₂SiO₃ (sodium silicate) as a precursor because of its low cost. Compared to TEOS, which controls the pH using a basic catalyst, Na₂SiO₃ controls the pH using an acid catalyst, giving a uniform coating. The coating thickness of TiO₂ is controlled using a surface modifier, cetrimonium bromide, which is used in various applications. The shape and thickness of the nanosized coating layer on TiO₂ are analyzed using transmission electron microscopy, and the SiO₂ nanoparticle behavior in terms of the before-and-after size distribution is measured using a particle size analyzer. The color measurements of the SiO₂ pigment are performed using UV-visible spectroscopy.

• Advances in nano research
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• 제15권4호
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• pp.295-304
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• 2023

In this paper, a powerful photocatalyst based on carbon nanocomposite is developed in order to obtain a new material applicable in water treatment and especially for the discoloration of effluents used in the textile industry. For that, TiO₂-graphene nanocomposites have been successfully synthesized by a mixture of Functionalized Graphene Sheet (FGS) and tetrachlorotitanium complexes to form FGS-TiO₂ nanocomposite. In the presence of an anionic surfactant, we used a new chemical process to functionalize graphene sheets in order to make them an excellent medium for blocking and preventing the aggregation of TiO₂ nanoparticles. The components of these nanocomposites are characterized by means of X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), which confirms the successful formation of the FGS-TiO₂ nanocomposite. It was found that the TiO₂ nanoparticles were dispersed uniformly on the graphene plane which possesses better charge separation capability than pure TiO₂. The FGS-TiO₂ nanocomposites exhibited higher photocatalytic activity compared to pure TiO₂ for the removal of three dyes: such as Methylene Blue (MB), Bromophenol Blue (BB) and Alizarin Red-S (AR) in water. The removal process was fast and more efficient with FGS-TiO₂ nanocomposite in daylight (in the absence of UV irradiation) compared to pure TiO₂ nanoparticles without and under UV in all pH range.