• Title/Summary/Keyword: UV transmission spectra

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Effects of UV Absorber and HALS(Hindered Amine Light Stabilizer) Addition in Water-soluble Acrylic Resin on Discoloration of Larix leptolepis (S. et Z.) Gordon (수용성(水溶性) 아크릴 수지(樹脂)의 자외선(紫外線) 흡수제(吸收劑)와 HALS 첨가(添加)가 일본잎갈나무의 변색(變色)에 미치는 영향(影響))

  • Kang, Kyoung-Taek;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.47-55
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    • 1996
  • UV transmission spectra of water-soluble acrylic resin films containing hydroxybenzophenolic, hydroxyphenylbenzotriazolic UV absorber and HALS(hindered amine light stabilizer) were investigated by exposure time(before exposure weathered for 160 and 320hours) in QUV Weather-Ometer. Also the YID(yellowness index difference), LID(lightness index difference) and CD(color difference) of dried water-soluble acrylic resin films and the coated woods of Larix leptolepis were analyzed by addition level of UV absorber(0, 1, 2 and 3%) and HALS(0, 0.5, 1 and 1.5%) and by exposure time in QUV Weather-Ometer. They showed no significant effects on UV transmission spectra of dried water-soluble acrylic resin films in the range of 300 to 400nm irrespective of exposure time. However, UV transmission decreased as increase of exposure time. UV transmission spectra were lower in dried water-soluble acrylic resin films containing hydroxybenzophenolic UV absorber and HALS than in these containing hydroxyphenylbenzotriazolic UV absorber and HALS in the range of 350 to 400nm. The least YID, LID and CD in the coated woods of Larix leptolepis appeared at the addition level of 3%, based on non-volatile content, in hydroxybenzophenolic and hydroxyphenylbenzotriazolic UV absorber, and of 1.5% in HALS to water-soluble acrylic resin.

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A Study on the UV-cut Properties of Cotton Fabrics Treated with UV-absorber (자외선 흡수제 처리 면직물의 소비성능 개선(제1보) - 자외선 차단성능에 관한 연구 -)

  • 강미정;권영아
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.5
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    • pp.925-932
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    • 2001
  • The influence of ultraviolet(UV)-ray in sun light on human skin has been noted. Textiles can provide protection against harmful UV-radiation. Normally UV-absorbing finishes are used to get better protection. The purpose of this study is to evaluate the UV-cut properties of cotton fabrics treated with UV-absorber. 2,2-dihydroxy-4,4-dimethoxbenzophenone, as UV-absorber was applied to 100% cotton fabric. Reagents added in finishing solution were Triton X-100, polyethylene glycol 400, and $MgCl_2{\cdot}6H_2O$, and C.I. Direct Red 81. Both untreated and treated cotton fabrics were exposed to a xenon arc lamp for 20 and 80 hours. UV absorption spectra of finishing solutions and UV transmission spectra of fabrics were measured by the UV/VIS spectrophotometer. The results of this study can be summarized as follows. The results of this study can be summarized as follows. Absorption and the related transmission spectra were modified in a controlled way with UV-absorber. Absorption effect of UV-absorber was improved by adding Triton X-100, PEG 400, and $MgCl_2{\cdot}6H_2O$ in finishing solution. The UV absorption of finishing solution was in the following order: U/D/T/P/M>D/T/P/M> D/T> D/P, D>U/T/P/M>U/T>T/P/M>T. The UV transmittance of cotton fabrics was remarkably decreased by the application of UV-absorber and additives. The UV-cut properties were most improved by the application of U/D/T/P/M.

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A Study on UV Degradation of SBR and NR Containing Polymeric UV Stabilizer (고분자형 자외선 안정제를 함유한 SBR과 NR의 UV 노화 거동에 관한 연구)

  • Kaang, Shin-Young;Nam, Kyoung-Tae;Hong, Chang-Kook;Chae, Kyu-Ho
    • Elastomers and Composites
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    • v.41 no.3
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    • pp.182-193
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    • 2006
  • The retardation effects of a new polymeric UV stabilizer, DGEBA-HALS, on the UV degradation of SBR and NR were investigated in this study. The UV degradation behaviors of three different rubber compounds, without any photostabilizer and with commercial Cyabsorb UV-3529 and DGEBA-HALS, were compared. Also, the physical characteristics such as Young's modulus, tensile strength, blow-off deformation and crosslink density were examined. The Young's modulus was increased by UV irradiation for all samples, and the tensile strength, after UV irradiation, of the compound with UV stabilizer was better than that of the compound without stabilizer. Especially, the tensile strength of UV irradiated NR was improved by adding DGEBA-HALS. The results of blow-off deformation were in accord with those of Young's modulus. The degree of transmission of SBR compounds obtained from UV-vis transmission spectra was improved about 4% by adding the UV stabilizer. Commercial Cyabsorb UJV-3529 and DGEBA-HALS showed similar trends of transmission. The SEM photographs of SBR surface showed that the size of cracks created by UV irradiation became smaller by adding UV stabilizer. In particular, it is observed that the stabilization effect of DGEBA-HALS was better than that of commercial Cyabsorb UV-3529.

The Effect of Gas Environment on the Electronic and Optical Properties of Amorphous Indium Zinc Tin Oxide Thin Films

  • Denny, Yus Rama;Lee, Sun-Young;Lee, Kang-Il;Seo, Soon-Joo;Oh, Suhk-Kun;Kang, Hee-Jae;Heo, Sung;Chung, Jae-Gwan;Lee, Jae-Cheol;Tougaard, Seven
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.141-141
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    • 2012
  • The electronic and optical properties of Indium Zinc Tin Oxide (IZTO) thin films using gas environment were investigated by X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS). REELS spectra revealed that the band gaps of IZTO thin films are 3.26, 3.07, and 3.46 eV for water mixed with oxygen, argon mixed with oxygen, and air environments, respectively. The measured band gaps by REELS are consistent with the optical band gaps obtained by UV-Spectrometer. The optical properties represented by the dielectric function $\mathfrak{m}$, the refractive index n, the extinction coefficient k, and the transmission coefficient T of the IZTO thin films with different gas environments were determined from a quantitative analysis of REELS spectra. The calculated transmission from quantitative analysis of REELS spectra shows good agreement with transmission measured by UV-spectrometer. The transmission values of 89% and low electrical resistivity of $3.55{\times}10^{-3}{\Omega}{\cdot}cm$ have been achieved for argon mixed with oxygen which indicates that the gas enviroment plays an important role in improving the electronic and optical properties of films.

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UV-cut Lens Manufacture using Optical Absorption Edge Control (광흡수단을 제어를 이용한 UV 차단렌즈 개발)

  • Kim, Yong Geun;Park, Dong Hwa;Sung, Jung Sub
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.1
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    • pp.29-34
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    • 2002
  • Because do dilution (5%) in Venzotriazol distilled water and is kept UV interception departure woe which make to time each 1, 2, 5, 15, 20, 30 minutes by dip method, produced sample ore of UV interception lens. Spectrum of transmittance for each sample are measured in 320~450nm sacred grounds. The result optical absorption edge is each 403, 408, 414, 419nm regions, and absorption edge appeared in each band of 3.07, 3.04, 2.99, 2.96 eV. UV-cut lens departure solution make 2-Hydroxy-4-n-octoxyhenzophenones of 5%, 10% because solvent methanol and UV-cut lens made by Spray pyrolysis method. Transmission edge of each lens that do spray to same warelength showed sameinwavelength spectra. Being storehouse absorption edgethat increase 385, 398 and 417nm region of when do spray for 2, 4 and 6 minutes, band is accomplishing each 3.22, 3.11, 2.97 eV.

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Synthesis of Praseodymium-Doped TiO2 Nanocatalysts by Sol-Microwave and Their Photocatalytic Activity Study

  • Huang, Fengping;Wang, Shuai;Zhang, Shuang;Fan, Yingge;Li, Chunxue;Wang, Chuang;Liu, Chun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.8
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    • pp.2512-2518
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    • 2014
  • The praseodymium-doped $TiO_2$ photocatalyst samples, which could degrade methyl orange under UV irradiation, were prepared by sol-microwave method for improving the photocatalytic activity of $TiO_2$. The resulting materials were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectra, Fourier transform infrared spectra (FTIR) and Ultraviolet-visible diffuse reflectance spectra (UV-vis DRS). It was found Pr doping retarded the growth of crystalline size and the phase transformation from anatase to rutile, and narrowed the band gap energy. Praseodymium doping brought about remarkable improvement in the photoactivity. The optimal dopant amount of Pr was 2% by molar of cement and the calcination temperature was $500^{\circ}C$ for the best photocatalytic activity. The improvement of photocatalytic activity was ascribed to the occurrence of lattice distortion and the effective containment of the recombination of the electron-hole by $Pr^{3+}$.

Study of Nano-scale Fullerene (C60) Clusters Formed in Micro-sized Droplet by UV Irradiation

  • Yeo, Seung-Jun;Ahn, Jeung-Sun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.571-571
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    • 2012
  • We discovered the formation of C60 aggregates in solution by means of photoluminescence spectroscopic study on C60 in solutions. From the in-depth investigation of temperature dependence of the luminescence of C60 in toluene, benzene and CS2 solutions, we reported that the C60 aggregates are formed during cooling at the freezing temperature of these solvents. Furthermore, the C60 aggregates can be changed to stable structures by irradiating with UV pulse-laser (Nd:YAG laser, 355nm). As a consequence, we could obtain nano-scale photo-polymerized C60 clusters, which appear as round-shaped nano- scale particles in high resolution transmission electron-microscopy (HRTEM) images. However, the yield of the nano-scale C60 clusters obtained by this method is too small. So we designed and developed a system to obtain C60 cluster of macroscopic quantity by using ultrasonic nebulizer. In this system, C60 solution was vaporized to several micro-sized droplets in vacuum, resulting in the formation of C60 aggregates by evaporating solvent (toluene). The system was invented to produce nano-scale carbon clusters by the irradiation of UV light upon C60 aggregates in vacuum. We have characterized the products, C60 cluster, obtained from the system by using UV absorption spectra and HPLC spectra. Although the products have a possibility of inclusion various forms of C60 cluster, results support that the product formed from the system by using vaporizer method establishes a new method to obtain C60 cluster in macroscopic quantity. In the presentation, the details of the system and the results of characterization are reported.

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A Study on the Molecular Orientation and the Surface Mophology of polyimide precursor ultrathin film (폴리이미드 전구체 초박막의 분자배향과 표면상태에 관한 연구)

  • Jeong, Soon-Wook
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.3
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    • pp.228-233
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    • 2005
  • Langmuir-Blodgett(LB) technique can speak the best candidate of the future molecular electronic devices. But, precursor as molecular ultrathin film devices require the bulk property that are influenced by the molecular orientation. So, this device is one of current interest in molecular electronic device development of new materials. In this study, quantitative evaluation of molecular orientation in LB films of polyamic acid alkylamine salt was performed analysis experiment comparing the absorption or transmission intensity of the FT-IR spectrometer and reflection or absorption spectra with UV-visible absorption spectra. It could find that the polar angle(${\theta}$) of the dipole moment appears in about $68^{\circ}$ and the tilting angle of the alkyl chain is about $11.5^{\circ}$.

A Study on the Molecular Orientation of Po1yamic Acid Alkylamine Salt Langmuir-Blodgett Films (Polyamic Acid 알킬아민 염 랭뮤어-블로젯막의 분자 배향에 관한 연구)

  • 정순욱;임현성
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.53.1-56
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    • 2000
  • Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle($\theta$) of the dipole moment is about 68$^{\circ}$and the tilting angle of the alkyl chain is about $11.5^{\circ}$ .

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Structure and Photoluminescence Properties of SnO2/Zn Core-shell Nanowires

  • Kim, Hyoun Woo;Na, Han Gil;Kwon, Yong Jung;Cho, Hong Yeon
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.241-241
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    • 2014
  • $SnO_2-core/Zn-shell$ heteronanowires were fabricated by a two-step process: thermal evaporation of Sn powders and employing a sputtering technique with a Zn target. X-ray diffraction, high-resolution transmission electron microscopy, and EDX spectra coincidentally indicated that the shell layer comprised the Zn phase. From Gaussian deconvolution studies, we observed that photoluminescence (PL) spectra consisted of yellow, green, and ultraviolet (UV) emission bands, regardless of shell-coating. We speculated the possible mechanisms of these emission peaks.

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