• Title/Summary/Keyword: Raman Spectroscopy

Search Result 1,141, Processing Time 0.026 seconds

Determining the Dynamic Sequence of Carbonyl Groups in a Rod-Coil Liquid Crystalline Oligomer Using Two-Dimensional Raman Correlation Spectroscopy (액정올리고머에 있는 카보닐그룹들의 동적순서에 대한 2차원 라만상관분광법 연구)

  • Jung, Kab-Sang;Yu, Soo-Chang;Han Yu, Keon-Ok
    • Journal of the Korean Chemical Society
    • /
    • v.48 no.3
    • /
    • pp.261-265
    • /
    • 2004
  • We investigated the order of local movement of functional groups (-C(=O)O) in a liquid crystalline (LC) oligomer (12-4) using 2D Raman correlation spectroscopy. The results suggest that the free carbonyl near the ethyl terminal group moved first, followed by the hydrogen-bonded group. The free carbonyl group between the biphenyl groups rarely moved. Interestingly, 2D sample-to-sample correlation spectroscopy (2D STSCS) revealed that some of the carbonyl modes started to move at far below (50$^{\circ}C$) the LC temperature (135$^{\circ}C$), countering conventional beliefs.

Surface-enhanced Raman scattering (SERS) spectroscopy: a versatile spectroscopic and analytical technique used in nanoscience and nanotechnology

  • Sur, Ujjal Kumar
    • Advances in nano research
    • /
    • v.1 no.2
    • /
    • pp.111-124
    • /
    • 2013
  • Surface-enhanced Raman scattering (SERS) effect deals with the enhancement of the Raman scattering intensity by molecules in the presence of a nanostructured metallic surface. The first observation of surface-enhanced Raman spectra was in 1974, when Fleischmann and his group at the University of Southampton, reported the first high-quality Raman spectra of monolayer-adsorbed pyridine on an electrochemically roughened Ag electrode surface. Over the last thirty years, it has developed into a versatile spectroscopic and analytical technique due to the rapid and explosive progress of nanoscience and nanotechnology. This review article describes the recent development in field of surface-enhanced Raman scattering research, especially fabrication of various SERS active substrates, mechanism of SERS effect and its various applications in both surface sciences and analytical sciences.

Studies on Printability of Amphoteric Latex-Based Coated Paper(I) - Orientation of Benzene Ring in the Latex Film - (내성(耐性) 라텍스를 이용한 도공지(塗工紙)의 인쇄적성(印刷適性)에 관한 연구(硏究)(I) - 라텍스필름에서 벤젠환의 배향성(配向性) -)

  • Lee, Yong-Kyu
    • Journal of the Korean Wood Science and Technology
    • /
    • v.22 no.1
    • /
    • pp.80-84
    • /
    • 1994
  • The orientation of bezene ring in latex film was investigated with raman spectroscopy. The benzene ring of anionic latex ran parallel with the film surface of latex, whereas that of amphoteric latex did not. Consequently, it showed the possibility of interactions or interrelations between the orientation of benzene ring and ink, contact angle, printability and so on.

  • PDF

Analysis of RBC Damage Using Laser Tweezers Raman Spectroscopy (LTRS) During Femtosecond Laser Optical Trapping (레이저 트위저 라만 분광을 이용한 펨토초 광포획 동안의 적혈구 손상 분석)

  • Ju, Seong-Bin;Pyo, Jin-U;Jang, Jae-Yeong;Lee, Seung-Deok;Kim, Beop-Min
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2008.02a
    • /
    • pp.453-454
    • /
    • 2008
  • femtosecond laser를 광원으로 하는 optical tweezers는 광포획 뿐만 아니라 비선형 현상을 발생시킬 수 있다는 장점을 가지고 있다. 그러나 높은 첨두 출력에 의하여 포획된 세포는 쉽게 손상되어 질 수 있다. 본 논문에서는 LTRS(Laser Tweezers Raman Spectroscopy)를 통하여 femtosecond laser와 CW laser에 의한 optical tweezers 상에서의 optical damage를 비교, 분석하였다.

  • PDF

Study of Molecular Reorientation in Liquid with Raman Spectroscopy. Intermolecular Interaction of Hexafluorobenzene with Benzene

  • Hwang, Hyun-Jin;Kim, Kwan;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
    • /
    • v.5 no.6
    • /
    • pp.245-248
    • /
    • 1984
  • Raman spectroscopy was used to study the reorientational motion of hexafluorobenzene in benzene and also in neutral solvents. From the viscosity dependence of the reorientation time, intermolecular interaction in the systems was investigated. No evidence was found to support the presence of long-lived 1:1 complex of hexafluorobenzene and benzene. The unusual viscosity dependence of the reorientational motion observed in the systems was explained as due to the formation of transient complexes.

Adsorption of Some Aliphatic Dimercaptans on the Silver Surface Investigated by Raman Spectroscopy

  • Kwon, Cheol-Kee;Kim, Kwan;Kim, Myung-Soo;Lee, Soon-Bo
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.3
    • /
    • pp.254-258
    • /
    • 1989
  • Adsorption of 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, and 1,6-hexanedithiol on silver surface has been investigated by surface-enhanced Raman spectroscopy. It has been found that the conformations of the adsorbates were mainly affected by steric interaction of the adsorbates with the surface. As the alkyl chain length separating the thiol groups increased, surface stacking efficiency became increasingly important in determining conformation of the adsorbate on the surface.

Measurement of CO Q-branch Raman Spectrum by using High Resolution Inverse Raman Spectrometer (고분해능 Inverse 라만 분광기를 이용한 CO Q-branch 라만 분광 측정)

  • 한재원
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 1989.02a
    • /
    • pp.59-64
    • /
    • 1989
  • Raman vibrational Q0branch spectra of pure CO are measured by using the technique of quasicw inverse Raman spectroscopy utilizing a pulsed single-frequency laser source. This approach gives enhanced sensitivity compared to earlier work which employed CW lasers, allowing extension of that work to higher accuracy, higher J states, and higher pressure. Fitting laws with pertubation theory and modified energy gap(MEG) theory are described, and the line broadening and shifting coefficients of J=0 to 24 are determined with both fitting laws.

  • PDF

A Spectral Comparison Study of PDT Drugs - ALA and ALA-Hexyl ester

  • Yao, Chen-Ji;Peng Qian;JodI H-J
    • Journal of Photoscience
    • /
    • v.9 no.2
    • /
    • pp.521-523
    • /
    • 2002
  • 5-aminolevulinic acid (ALA) has been used to stimulate endogenous protoporphyrin IX (PpIX) in tumor and then initiate PDT. Recently, ALA-Hexyl ester (He-ALA) was found much effective than ALA on producing PpIX in cancer cells. To clarify the transportation mechanism of ALA and He-ALA, the detection of them is the important step. ALA and its derivatives all don't emit fluorescence, so the Raman spectroscopy was used here for the direct detection of ALA and He-ALA. The results showed that ALA and He-ALA have the common strong Raman peaks at 2930, 2950 CM$\^$-1/, due to the CH$_2$ vibration. The peak 3050 CM$\^$-1/ appeared in ALA spectrum can be attributed to OH vibration, while the peaks of 2860, 2900 CM$\^$-1/ in He-ALA spectrum were assigned as the modes of CH$_3$. This Raman spectral characteristic is consistence with the structure difference of He-ALA and ALA. Thus, Raman spectroscopy provides a new way to detect and distinguish ALA and He-ALA, and could be explored further in biology system.

  • PDF

Stellar Wind Accretion and Raman O VI Spectroscopy of the Symbiotic Star AG Draconis

  • Lee, Young-Min;Lee, Hee-Won;Lee, Ho-Gyu;Angeloni, Rodolfo
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.43 no.1
    • /
    • pp.63.4-64
    • /
    • 2018
  • High resolution spectroscopy of the yellow symbiotic star AG Draconis is performed with the Canada-France-Hawaii Telescope to analyse the line profiles of Raman scattered O VI broad emission features at $6825{\AA}$ and $7082{\AA}$ with a view to investigating the wind accretion process from the mass losing giant to the white dwarf. These two spectral features are formed through inelastic scattering of O $VI{\lambda}{\lambda}32$ and 1038 with atomic hydrogen. We find that these features exhibit double-component profiles with red parts stronger than blue ones with the velocity separation of ~ 60 km s-1 in the O VI velocity space. Monte Carlo simulations for O VI line radiative transfer are performed by assuming that the O VI emission region constitutes a part of the accretion flow around the white dwarf and that Raman O VI features are formed in the neutral part of the slow stellar wind from the giant companion. The overall Raman O VI profiles are reasonably fit with an azimuthally asymmetric accretion flow and the mass loss rate ~ 4 ${\times}$ 10^{-7} M_sun yr^{-1}. We also find that additional bipolar neutral regions moving away with a speed ~ 70 km s^{-1} in the directions perpendicular to the orbital plane provide considerably improved fit to the red wing parts of Raman features.

  • PDF