• 제목/요약/키워드: FT-IR Spectroscopy

검색결과 855건 처리시간 0.031초

폴리애미드 배향막의 편광 자외선 조사에 따른 액정 배향 메카니즘 (Mechanism of Orientation of Liquid Crystal Molecules for Polarized UV-exposed Polyimide Alignment Layers)

  • 김일형;김욱수;하기룡
    • 폴리머
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    • 제26권2호
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    • pp.209-217
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    • 2002
  • 편광 푸리에 변환 적외선 분광법과 자외선 분광법을 이용하여 액정 display (LCD)의 배향막으로 널리 사용되는 폴리이미드 (PI) 필름의 편광 자외선 (PUV) 조사에 따른 액정의 배향 메카니즘을 연구하였다. UV 측정 결과, PI 필름은 360 nm 이하 파장의 자외선을 주로 흡수하여 광화학 반응이 유도됨을 알 수 있었다. 또한, PUV가 조사된 PI의 경우, PI 분자들의 분해로 인해 FT-IR 흡수 피크들의 강도가 조사시간에 따라 감소하였고, $3244 cm^{-1}$ 부근에서 완만한 곡선 형태의 새로운 피크가 형성되었다. 또한 조사된 PUV의 극성 방향에 평행한 PI 분자들의 우선적인 광분해 반응으로 인하여 PUV 조사 후 남아 있는 PI 분자들은 조사된 PUV 극성 방향과 수직 배향을 나타내었다. 하지만 러빙 처리된 PI 필름은 러빙 방향과 평행하게 PI 분자들의 재배향이 유도됨을 확인하였다. 또한 러빙 처리 및 PUV가 조사된 PI 배향막을 차용하여 제조된 액정 셀에서는 액정이 러빙 방향에 대해서는 평행하게, 조사된 PUV의 극성방향과는 수직으로 배향함을 확인하였다.

산업폐수중 Chromate이온 처리용 소재특성 (Properties of Materials for Treatment of Chromate in Industrial Wastewater)

  • 전용진;김영준;홍영호
    • 한국산학기술학회논문지
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    • 제5권2호
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    • pp.103-107
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    • 2004
  • 산업폐수중 anion인 chromate(CrO4-²)처리에 필요한 기능성소재로 이온교환 및 흡착기능을 가진 PAN계 이온교환섬유를 제조하고 성능평가를 실시하여 소재특성을 연구하였다. Poly(acrylonitrile)섬유와 diethyletriamine을 /sup AlCl₃ 촉매 하에서 반응시켜 poly (acryloamidino diethylenediamine)을 제조하고, /sup 13/C-NMR분석으로 확인하였다. 온도에 따른 polymer의 개질반응 정도를 FT-IR 분석으로 조사하여 개질반응의 최적 온도 120℃를 확인하였다. 개질반응된 polymer의 chromate 최대 흡착량을 분석하고, 음이온 흡착에 대한 소재특성을 pH별로 실시하였다. poly(acryloamidino diethylenediamine)/CrO4-² coordinaion 과정의 FT-IR spectra 분석하여 분자내, 분자간 결합형태를 밝히고 coordination된 구조를 제시하였다.

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FT-IR and X-Ray Diffraction Characterization of Melanoidins Formed from Glucose and Fructose with Amino Acid Enantiomers in the Maillard Reaction

  • Kim, Ji-Sang;Lee, Young-Soon
    • Food Science and Biotechnology
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    • 제18권2호
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    • pp.546-551
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    • 2009
  • The objective of this study was to investigate Fourier transform infrared (FT-IR) spectrometry and the X-ray diffraction (XRD) characterization of melanoidins formed from glucose and fructose with amino acid enantiomers in the Maillard reaction. Before dialysis, FT-IR spectroscopy of all the samples showed that the characteristic absorption intensities appeared as a broad and intense band of the stretching vibration of the -OH group at 3,400/cm for a high pH. The absorption bands of the melanoidins sharply decreased in intensity after dialysis as compared to those before dialysis. In particular, the absorption bands at 992 and 575/cm disappeared. The XRD confirmed that the crystal structure of the melanoidins disappeared after dialysis and a new crystal structure was formed at 9 and $28^{\circ}$ ($2{\theta}$. In particular, broad diffraction peaks were formed in the $10-21^{\circ}$ ($2{\theta}$) range for a high pH, while other sharp diffraction peaks disappeared.

적외선 분광스펙트럼 및 기체크로마토그라피 분석 데이터의 다변량 통계분석을 이용한 대두 종자 지방산 함량예측 (Simultaneous estimation of fatty acids contents from soybean seeds using fourier transform infrared spectroscopy and gas chromatography by multivariate analysis)

  • 안명숙;지은이;송승엽;안준우;정원중;민성란;김석원
    • Journal of Plant Biotechnology
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    • 제42권1호
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    • pp.60-70
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    • 2015
  • 본 연구의 목적은 적외선 분광스펙트럼 데이터를 이용하여 대두 종자내의 지방산 함량을 동시에 예측할 수 있는지 여부를 조사하기 위한 것이다. 총 153종의 대두(Glycine max Merrill) 종자로부터 적외선 분광스펙트럼 및 지방산의 함량을 기체크로마토그라피 분석을 통하여 확인하였다. 적외선 분광스펙트럼 조사결과 대두는 단백질이나 아미노산의 amide bond region ($1,700{\sim}1,500cm^{-1}$), 핵산이나 인지질의 phosphodiester groups ($1,500{\sim}1,300cm^{-1}$) 그리고 탄수화물 등 다당류의 sugar region ($1,200{\sim}1,000cm^{-1}$)에서 계통별로 큰 차이가 이루어짐을 알 수 있었다. 총 29라인의 대두 계통별 시료로부터 지방산 함량을 조사한 결과 총 지방산의 함량은 건조 시료 0.1 g 당 $185.57{\mu}g$에서 $325.9{\mu}g$으로 계통간에 차이가 있었음을 알 수 있었으며 평균 함량은 $244.48{\mu}g$이었다. PLS regression 분석을 이용하여 총 5개 지방산(팔미틱산, 스테아릭산, 올레익산, 리노레익산 그리고 리노레닉산) 함량 예측 calibration models의 실측 검증 결과, 팔미틱산($R^2=0.8002$), 올레익산($R^2=0.8909$) 그리고 리노레익산($R^2=0.815$)은 회귀분석 상관계수가 0.8 이상으로 정확도 높음을 알 수 있었다. 그러나 스테아릭산($R^2=0.4598$)과 리노레닉산($R^2=0.6868$)의 경우 상관계수가 0.7 이하로 상대적으로 예측정확도가 낮음을 알 수 있었다. 본 연구에서 확립된 기술은 지방산의 조성 변환을 통하여 새로운 대두 품종 개발을 위한 계통선발 과정에서 매우 효율적인 수단으로 활용이 가능할 것으로 사료된다. 더 나아가 본 기술은 대두는 물론 대두 유래 농산물이나 식품의 품질 검증 수단으로 활용이 가능할 것으로 기대된다.

The Study on Characteristics of N-Doped Ethylcyclohexane Plasma-Polymer Thin Films

  • 서현진;조상진;이진우;전소현;부진효
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.540-540
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    • 2013
  • In this studying, we investigated the basic properties of N-doped plasma polymer. The N-doped ethylcyclohexane plasma polymer thin films were deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition method. Ethylcyclohexenewas used as organic precursor (carbon source) with hydrogen gas as the precursor bubbler gas. Additionally, ammonia gas [NH3] was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, Raman spectroscopy, FE-SEM, and water contact angle measurement. The ellipsometry results showed the refractive index change of the N-doped ethylcyclohexene plasma polymer film. The FT-IR spectrashowed that the N-doped ethylcyclohexene plasma polymer films were completely fragmented and polymerized from ethylcyclohexane.

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단양 현곡리 출토 고려시대 섬유류 및 지류 유물에 관한 연구 (Analyses on Artifacts of Koryo Kynasty Excavated from Hyungok-ni Danyang)

  • 안춘수;박희현
    • 한국의류학회지
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    • 제23권8호
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    • pp.1161-1169
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    • 1999
  • This research was aimed to identify the artifact type and their characteristics of the textile related materials excavated from Koryo Dynasty tombs of Hyungok-ni Danyang. Microscopy solubility test energy dispersive X-ray spectroscopy(EDS) and fourier transform infrared spectroscopy (FT-IR) fabric density test were used for the identification and when necessary standard samples were made in order to compare its characteristics with hose of the original artifact, the result indicated that the artifacts included both textile and paper. Artifacts from Burial 14 were comprised of textile fragments FT-IR and the solubility test conducted on the artifact indicated that the textiles were made with ramie woven with plain weave technique in a fairly loose fabric density. Rest of the artifacts were all comprised of paper.

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A facile green reduction of graphene oxide using Annona squamosa leaf extract

  • Chandu, Basavaiah;Mosali, Venkata Sai Sriram;Mullamuri, Bhanu;Bollikolla, Hari Babu
    • Carbon letters
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    • 제21권
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    • pp.74-80
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    • 2017
  • A highly facile and eco-friendly green synthesis of Annona squamosa (custard apple) leaf extract reduced graphene oxide (CRG) nanosheets was achieved by the reduction of graphene oxide (GO). The as-prepared CRG was characterized with X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Vis), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopic techniques. Removal of oxygen containing moieties from the GO was confirmed by UV-Vis, FT-IR and XPS spectroscopic data. The XRD and Raman data further confirmed the formation of the CRG. TEM images showed the sheet structure of the synthesized CRG. These results show that the phytochemicals present in custard apple leaf extract act as excellent reducing agents. The CRG showed good dispersion in water.

Preparation and Properties of Polyimides Having Highly Flexible Linkages and Their Nanocomposites with Organoclays

  • Cho, Young-Ho;Park, Jong-Min;Park, Yun-Heum
    • Macromolecular Research
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    • 제12권1호
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    • pp.38-45
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    • 2004
  • A highly flexible polyimide (PI) was synthesized successfully from ethylene glycol bis(anhydrotrimellitate) (TMEG) and 1,3-bis(4-aminophenoxy)benzene (TPER) for its application in electronics. To enhance the thermal stability and mechanical properties of this novel PI, we prepared PI nanocomposite films using nanoparticles of clays that had been treated with organic intercalating agents (organoclays). We used two types of organoclays: montmo-rillonite (MMT) treated with hexadecylamine (C$\_$16/) and MMT treated with dimethyl dihydrogenated tallow quaternary ammonium (l5A). PI/organoclay hybrid films were obtained by first preparing poly(amic acid) (PAA)/organoclay films and then converting the PAA to polyimide by thermal conversion. PAA was characterized by FT-IR and $^1$H-NMR spectroscopy and the conversion of PAA to PI was confirmed by FT-IR spectroscopy. We analyzed the dispersion of the organoclays in the PI film by X-ray diffraction. The thermal stability and mechanical properties of the hybrid films were also investigated.

Synthesis of N-doped Ethylcyclohexane Plasma Polymer Thin Films with Controlled Ammonia Flow Rate by PECVD Method

  • Seo, Hyunjin;Cho, Sang-Jin;Boo, Jin-Hyo
    • Applied Science and Convergence Technology
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    • 제23권1호
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    • pp.44-47
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    • 2014
  • In this study, we investigated the basic properties of N-doped ethylcyclohexene plasma polymer thin films that deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition (PECVD) method with controlled ammonia flow rate. Ethylcyclohexene was used as organic precursor with hydrogen gas as the precursor bubbler gas. Additionally, ammonia ($NH_3$) gas was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, UV-Visible spectroscopy, and water contact angle measurement. We found that with increasing plasma power, film thickness is gradually increased while optical transmittance is drastically decreased. However, under the same plasma condition, water contact angle is decreased with increasing $NH_3$ flow rate. The FT-IR spectra showed that the N-doped ethylcyclohexene plasma polymer films were completely fragmented and polymerized from ethylcyclohexane.

Extracted Catechin Incorporated Chitosan Patch for Dermal Drug Delivery Systems

  • Seunghwan Choy
    • 한국재료학회지
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    • 제33권11호
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    • pp.458-464
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    • 2023
  • In order to develop catechin patches for skin regeneration at wound sites, patches with varying concentrations of catechin and chitosan were manufactured. An optimal composition ratio was determined by adjusting the drug release rate and amount, to maximize efficiency. The catechin used in this study was extracted from green tea leaves using a solvent/ultrasonication method, and its characteristics were confirmed through Fourier transform-infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) analyses. Patches were prepared with different concentrations of catechin and chitosan, and various properties were analyzed using techniques such as FT-IR, water contact angle analysis, and UV-Vis spectroscopy. It was observed that as the chitosan concentration increased, the release of catechin slowed down or almost ceased. A patch manufactured with 1.5 mg/cm2 of catechin at a 1 % chitosan concentration exhibited a high initial release rate over 24 h and demonstrated cellular biocompatibility. Consequently, these patches, with tailored release characteristics based on the concentrations of chitosan and catechin, hold promise for use as drug delivery systems in wound healing applications.