• Title/Summary/Keyword: Fourier transform IR

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A Variety of Activation Methods Employed in “Activated-Ion” Electron Capture Dissociation Mass Spectrometry: A Test against Bovine Ubiquitin 7+ Ions

  • Oh, Han-Bin;McLafferty, Fred W.
    • Bulletin of the Korean Chemical Society
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    • v.27 no.3
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    • pp.389-394
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    • 2006
  • Fragmentation efficiencies of various ‘activated-ion’ electron capture dissociation (AI-ECD) methods are compared for a model system of bovine ubiquitin 7+ cations. In AI-ECD studies, sufficient internal energy was given to protein cations prior to ECD application using IR laser radiation, collisions, blackbody radiation, or in-beam collisions, in turn. The added energy was utilized in increasing the population of the precursor ions with less intra-molecular noncovalent bonds or enhancing thermal fluctuations of the protein cations. Removal of noncovalent bonds resulted in extended structures, which are ECD friendly. Under their best conditions, a variety of activation methods showed a similar effectiveness in ECD fragmentation. In terms of the number of fragmented inter-residue bonds, IR laser/blackbody infrared radiation and ‘in-beam’ activation were almost equally efficient with ~70% sequence coverage, while collisions were less productive. In particular, ‘in-beam’ activation showed an excellent effectiveness in characterizing a pre-fractionated single kind of protein species. However, its inherent procedure did not allow for isolation of the protein cations of interest.

Nanoparticle의 분산 안정도에 따른 ATR-FTIR 분석법을 이용한 증착소재 흡착특성연구

  • Kim, Jong-Ho;Park, Jae-Seo;shahzad, Rauf;Lee, Chang-Hui;Sin, Jae-Su;Gang, Sang-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.113-113
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    • 2016
  • 반도체 산업이 발전하고 기술이 향상됨에 따라 미세화되고 복잡한 구조의 소자가 개발되고 있으며, 2차원 소재 등 다양하고 새로운 소재들이 발견 및 연구되고 있다. 새로운 소재 또는 기술을 이용한 고품질 소자를 개발하기 위해서는 우수한 특성(높은 순도, 우수한 분해 및 반응 특성)을 지닌 증착소재의 개발 및 평가가 선행되어야 한다. 기존의 증착소재의 기본 물성을 측정하는 방법인 단순 기상 Fourier transform infrared spectroscopy(FT-IR) 분석법은 실제 공정에서의 증착경향을 대변하기 어렵다는 단점이 있다. 이러한 단점을 보완하기 위해 개조된 attenuated total reflection (ATR) 액세서리를 이용하여 실제 공정에서의 증착경향을 대변하고자 하였다. 본 연구에서는 반도체 증착소재의 분해 및 표면 흡착 특성을 분석하기 위해 ATR-FTIR 분석법을 이용하여 수행하였으며, 분산안정도에 따른 nanoparticle을 ATR의 크리스탈 표면에 분포시켜 hexamethyldisilazane(HMDS) source의 흡착 효율을 향상시키는 연구를 수행하였다. Nanoparticle의 분산안정도를 높이기 위하여 suspension 상태에서 pH, sonication, 분산제를 이용하였으며, nanoparticle을 ATR crystal 표면에 분포하여 분석한 결과, 분산안정도에 따라 HMDS의 흡착효율이 달라짐을 확인하였다.

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Synthesis and Characterization of Dimer Acid-Based Polyamides (다이머산계 폴리아미드의 합성 및 특성에 관한 연구)

  • Park, Hyun Ju;Jeon, Ho Kyun;Oh, Sang Taek
    • Journal of Adhesion and Interface
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    • v.17 no.4
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    • pp.136-140
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    • 2016
  • In this study, a series of dimer acid-based polyamides with different diamines were synthesized by condensation polymerization and the polyamides were characterized by Fourier transform infrared spectroscopy (FT-IR). Effects of diamine structures on mechanical and thermal properties of polyamides were investigated. The tensile strength and lap shear adhesion strength of aromatic-based polyamide (DAP) were higher than those of aliphatic-based polyamide (DAH). In DSC thermogram, DAP has a high $T_g$ and $T_m$ compared with DAH. DAP's and DAH's softening point were $112-115^{\circ}C$ and $98-121^{\circ}C$, respectively.

Preparation of Porous TiO2 Thin Films by Poly(vinyl chloride)-graft-poly(N-vinyl pyrrolidone) and Their Applications to Dye-sensitized Solar Cells

  • Yeon, Seung-Hyeon;Patel, Rajkumar;Koh, Jong-Kwan;Ahn, Sung-Hoon;Kim, Jong-Hak
    • Journal of the Korean Electrochemical Society
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    • v.14 no.2
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    • pp.83-91
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    • 2011
  • Mesoporous titanium dioxide ($TiO_2$) thin films were prepared using poly(vinyl chloride)-graft-poly(N-vinyl pyrrolidone) (PVC-g-PVP) as a templating agent via sol-gel process. Grafting of PVC chains from PVC backbone was done by atom transfer radical polymerization (ATRP) technique. The successful grafting of PVP to synthesize PVC-g-PVP was checked by fourier-transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC). The carbonyl group interaction of PVC-g-PVP graft copolymer with $TiO_2$ was confirmed by FT-IR. The porous morphologies of the $TiO_2$ films genereated after calcination at $450^{\circ}C$ was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mesoporous $TiO_2$ films with 580 nm in thickness were used as a photoelectrode for solid state dye sensitized solar cell (DSSC) and showed an energy conversion efficiency of 1.05% at 100 $mW/cm^2$.

Immobilization of Trypsin on Chitosan Nonwoven Using Glutaraldehyde (글루타알데하이드에 의한 키토산 부직포에 트립신 고정화)

  • Kim, Jung Soo;Lee, So Hee;Song, Wha Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.7
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    • pp.852-863
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    • 2013
  • We investigate the immobilization of trypsin on chitosan nonwoven using glutaraldehyde (GA). The conditions for trypsin on chitosan nonwoven and GA cross-linking were optimized depending on different conditions. The order of GA cross-linking was determined by the activity of immobilized trypsin. The characteristics of chitosan nonwoven were examined by Fourier-transform infrared (FT-IR) and surface morphology analyses (SEM). Results showed that the optimal treatment conditions for trypsin on chitosan nonwoven were as follows: pH 8.5; temperature $37^{\circ}C$; trypsin concentration 15% (o.w.f); and treatment time 60 min. Those for GA cross-linking were: pH 10.0; GA concentration 3% (v/v); and treatment time 120 min. FT-IR analysis showed that GA was cross-linked on chitosan nonwoven. The SEM analysis also showed that trypsin was immobilized on chitosan nonwoven.

Study on Type of Different Polyols for Physical Properties of Polyurethane Foam Under Sea Water (해수에서 폴리올 종류가 폴리우레탄 폼의 물성에 미치는 영향)

  • Kim, Sang-Bum
    • Elastomers and Composites
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    • v.46 no.2
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    • pp.158-163
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    • 2011
  • Rigid polyurethane foam (PUF) was synthesized with different contents of aliphatic polyester polyol, aromatic polyester polyol and aliphatic polyether polyol to know change of properties under sea water. UTM(universal testing machine), DSC(differential scanning calorimetry), hardness meter and FT-IR(Fourier transform spectroscopy) were used to study the PUF`s physical properties under sea water. Compressive strength and hardness of PUF decreased with increasing the content of aromatic polyester polyol under sea water as aging. According to the results of IR spectral analysis, reduction of urethane and urea peak was found and allophanate and biuret peak increased. Although glass transition temperature of PUF increased, mechanical properties of PUF decreased under sea water, because PUF gets brittle when crosslink density increase.

Synthesis and Characterization of Nanocomposite Films Consisting of Vanadium Oxide and Microphase-separated Graft Copolymer

  • Choi, Jin-Kyu;Kim, Yong-Woo;Koh, Joo-Hwan;Kim, Jong-Hak;Mayes, Anne M.
    • Macromolecular Research
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    • v.15 no.6
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    • pp.553-559
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    • 2007
  • Nanocomposite films were prepared by sol-gel synthesis from vanadium triisopropoxide with $poly((oxyethylene)_9$ methacrylate)-graft-poly(dimethyl siloxane), POEM-g-PDMS, producing in situ growth of vanadium oxide within the continuous ion-conducting POEM domains of micro phase-separated graft copolymer. The formation of vanadium oxide was confirmed by wide angle x-ray scattering (WAXS) and Fourier transform infrared (FT-IR) spectroscopy. Small angle x-ray scattering (SAXS) revealed the spatially-selective incorporation of vanadium oxide in the POEM domains. Upon the incorporation of vanadium oxide, the domain periodicity of the graft copolymer monotonously increased from 17.2 to 21.0 nm at a vanadium content 14 v%, above which it remained almost invariant. The selective interaction of vanadium oxide with POEM was further verified by differential scanning calorimetry (DSC) and FT-IR spectroscopy. The nanocomposite films exhibited excellent mechanical properties $(l0^{-5}-10^{-7}dyne/cm^2)$, mostly due to the confinement of vanadium oxide in the POEM chains as well as the interfaces created by the microphase separation of the graft copolymer.

Cytotoxic Activity of Biosynthesized Gold Nanoparticles with an Extract of the Red Seaweed Corallina officinalis on the MCF-7 Human Breast Cancer Cell Line

  • El-Kassas, Hala Yassin;El-Sheekh, Mostafa M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4311-4317
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    • 2014
  • Background: Nano-biotechnology is recognized as offering revolutionary changes in the field of cancer therapy and biologically synthesized gold nanoparticles are known to have a wide range of medical applications. Materials and Methods: Gold nanoparticles (GNPs) were biosynthesized with an aqueous extract of the red alga Corallina officinalis, used as a reducing and stabilizing agent. GNPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FT-IR) spectroscopy and tested for cytotoxic activity against human breast cancer (MCF-7) cells cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum, considering their cytotoxicty and effects on cellular DNA. Results: The biosynthesized GNPs were $14.6{\pm}1nm$ in diameter. FT-IR analysis showed that the hydroxyl functional group from polyphenols and carbonyl group from proteins could assist in formation and stabilization. The GNPs showed potent cytotoxic activity against MCF-7 cells, causing necrosis at high concentrations while lower concentrations were without effect as indicated by DNA fragmentation assay. Conclusions: The antitumor activity of the biosynthesized GNPs from the red alga Corallina officinalis against human breast cancer cells may be due to the cytotoxic effects of the gold nanoparticles and the polyphenolcontent of the algal extract.

A Study on Pre-bonding of 3C-SiC Wafers using CVD Oxide (CVD 절연막을 이용한 3C-SiC 기판의 초기직접접합에 관한 연구)

  • ;;Shigehiro Nishino
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.10
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    • pp.883-888
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    • 2002
  • SiC direct bonding technology is very attractive for both SiCOI(SiC-on-insulator) electric devices and SiC-MEMS(micro electro mechanical system) fields because of its application possibility in harsh environments. This paper presents pre-bonding techniques with variation of HF pre-treatment conditions for SiC wafer direct bonding using PECVD(plasma enhanced chemical vapor deposition) oxide. The PECYD oxide was characterized by XPS(X-ray photoelectron spectrometer) and AFM(atomic force microscopy). The characteristics of the bonded sample were measured under different bonding conditions of HF concentration and an applied pressure. The bonding strength was evaluated by the tensile strength method. The bonded interface was analyzed by using SEM(scanning electron microscope). Components existed in the interlayer were analyzed by using FT-IR(fourier transform infrared spectroscopy). The bonding strength was varied with HF pre-treatment conditions before the pre-bonding in the range of 5.3 kgf/cm$^2$to 15.5 kgf/cm$^2$.

Development of DNA Sensor Using Magnetic Iron Oxide Nanoparticle (자성 산화철(iron oxide) 나노입자를 이용한 DNA 센서 개발)

  • Nam, Ki-Chang;Song, Kwang-Soup
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.6
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    • pp.51-56
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    • 2011
  • The surface of magnetic iron oxide nanoparticles (${\gamma}-Fe_2O_3$) is functionalized ($-NH_2$, -COOH) with bifunctional organic molecules and evaluated using FT-IR (Fourier transform infrared spectroscopy). We immobilize 21-base pair probe DNA and hybridize fluorescence-labeled (Cy5) target DNA onto the functionalized iron oxide nanoparticles. The fluorescence images obtained from a confocal microscopy show that the functionalized iron oxide nanoparticles should detect the hybridization of complementary and noncomplementary DNA.