Fourier polarization spectroscopy

The poly(L-lysine) formed a-helical rods in the multilayers that are aligned along the scratching direction of the substrate. He applied attenuated total reflection-Fourier transform spectroscopy (ATR-FTIR) using polarized light for the determination of the orientation within the films. 

Therefore, X-ray photoelectron spectroscopy (XPS) [12, 16,17] and diffuse reflection infrared Fourier transform spectroscopy (DRIFT) [17] are used to analyse the chemical composition of the metal surface and the amount of the surface-bonded polymer after the adsorption processes. For the ZnO/PVFA-co-PVAm composites solvatochromic dyes were employed to evaluate changes in the surface polarity after the polymer adsorption [18-22],... 

Siesler, H.W., Zebger, L, Kulinna, C Okretic, S., Shilov, S. and Hoffmann, U. (1999) Segmental mobility oF liquid crystals and liquid-crystalline polymers under external fields characterization by fourier-transform infrared polarization spectroscopy, in Modem Polymer Spectroscopy (ed. G. Zerbi), Wiley-VCH Verlag GmbH, Weinheim, p. 33. 

The primary components and the chemical structure of the raw peat and the solid product were further analyzed by Fourier transform infrared spectroscopy (FTIR) 0ASCO 670 Plus) using the Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) technique and the JASCO IR Mentor Pro 6.5 software for spectral analysis. The cross polarization/magic angle spinning (CP/MAS) NMR spectrum of raw peat and the solid... 

Segmental Mobility of Liquid Crystals and Liquid-Crystalline Polymers under External Fields Characterization by Fourier-transform Infrared Polarization Spectroscopy... 

Chapters 1 and 2 introduce new experimental techniques that provide new sets of relevant data for the study of the local and overall mobility of polymer chains. In Chapter 1, the development of two-dimensional infrared spectroscopy is described with a discussion of the mathematical principles, the description of the instrumental technique, and a detailed analysis of a few cases. In Chapter 2 the success of Fourier transform infrared polarization spectroscopy is shown for the study of segmental mobility in a polymer or a liquid-crystalline polymer under the influence of an external directional perturbation such as electric, electromagnetic, or mechanical forces. Industrial research laboratories should pay much attention to the information which can be acquired with this technique for technologically relevant polymeric materials. 

With the continuous developments, IR spectroscopy became the most widely used characterization technique in industry and in many technological processes, e.g. in food sciences. However, modern applications such as IR microspectroscopy require intense, brilliant and broadband sources, so that research has been oriented towards new IR sources. Actually, Fourier transform spectroscopy strongly benefits from a broadband non-thermal source such as SR that not only fulfils these requirements but also exhibits well-defined polarization properties and time structure. 

The improvement of the methodology, namely, the use of other modulation techniques such as polarization modulation and Fourier transform spectroscopy. 

The general task is to trace the evolution of the third order polarization of the material created by each of the above 12 Raman field operators. For brevity, we choose to select only the subset of eight that is based on two colours only—a situation that is connnon to almost all of the Raman spectroscopies. Tliree-coloiir Raman studies are rather rare, but are most interesting, as demonstrated at both third and fifth order by the work in Wright s laboratory [21, 22, 23 and 24]- That work anticipates variations that include infrared resonances and the birth of doubly resonant vibrational spectroscopy (DOVE) and its two-dimensional Fourier transfomi representations analogous to 2D NMR [25]. 

Clip acts in phase (the same Fourier component) with the first action of cii to produce a polarization that is anti-Stokes shifted from oi (see fV (E) and IFj (F) of figure B 1.3.2(b)). For the case of CSRS the third field action has frequency CO2 and acts in phase with the earlier action of CO2 (W (C) and IFj (D) of figure Bl.3.2 (b). Unlike the Class I spectroscopies, no fields in CARS or CSRS (or any homodyne detected Class II spectroscopies) are in quadrature at the polarization level. Since homodyne detected CRS is governed by the modulus square of hs lineshape is not a synmretric lineshape like those in the Class I... 

An alternative approach to obtaining microwave spectroscopy is Fourier transfonn microwave (FTMW) spectroscopy in a molecular beam [10], This may be considered as the microwave analogue of Fourier transfonn NMR spectroscopy. The molecular beam passes into a Fabry-Perot cavity, where it is subjected to a short microwave pulse (of a few milliseconds duration). This creates a macroscopic polarization of the molecules. After the microwave pulse, the time-domain signal due to coherent emission by the polarized molecules is detected and Fourier transfonned to obtain the microwave spectmm. 

The role of specific interactions in the plasticization of PVC has been proposed from work on specific interactions of esters in solvents (eg, hydrogenated chlorocarbons) (13), work on blends of polyesters with PVC (14—19), and work on plasticized PVC itself (20—23). Modes of iateraction between the carbonyl functionaHty of the plasticizer ester or polyester were proposed, mostly on the basis of results from Fourier transform infrared spectroscopy (ftir). Shifts in the absorption frequency of the carbonyl group of the plasticizer ester to lower wave number, indicative of a reduction in polarity (ie, some iateraction between this functionaHty and the polymer) have been reported (20—22). Work performed with dibutyl phthalate (22) suggests an optimum concentration at which such iateractions are maximized. Spectral shifts are in the range 3—8 cm . Similar shifts have also been reported in blends of PVC with polyesters (14—20), again showing a concentration dependence of the shift to lower wave number of the ester carbonyl absorption frequency. 

Recent work in our laboratory has shown that Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) can be used routinely to measure vibrational spectra of a monolayer on a low area metal surface. To achieve sensitivity and resolution, a pseudo-double beam, polarization modulation technique was integrated into the FT-IR experiment. We have shown applicability of FT-IRRAS to spectral measurements of surface adsorbates in the presence of a surrounding infrared absorbing gas or liquid as well as measurements in the UHV. We now show progress toward situ measurement of thermal and hydration induced conformational changes of adsorbate structure. The design of the cell and some preliminary measurements will be discussed. 

The availability of the purified transporter in large quantity has enabled investigation of its secondary structure by biophysical techniques. Comparison of the circular dichroism (CD) spectrum of the transporter in lipid vesicles with the CD spectra of water-soluble proteins of known structure indicated the presence of approximately 82% a-helix, 10% ) -turns and 8% other random coil structure [97]. No / -sheet structure was detected either in this study or in a study of the protein by the same group using polarized Fourier transform infrared (FTIR) spectroscopy [98]. In our laboratory FTIR spectroscopy of the transporter has similarly revealed that... 

Polarization Fourier transform infrared surface spectroscopy makes use of light beams polarized in two mutually perpendicular directions (Fig. 3.2), surface-parallel (s-polarization) and surface-normal (p-polarization). 

One of the major obstacles to investigating ultrathin polymer films is the small amount of detectable sample material and, as a result, high instrument sensitivity is crucial. Although polarized Fourier Transform Infrared Spectroscopy (13.141 has... 

This restilt was confimed by other groupsi2.i3, using Fourier transform infrared spectroscopy. Kunimatsu and Kita made further progress using polarization modulation to enable quantitative measurements and showed... 

Probing Metalloproteins Electronic absorption spectroscopy of copper proteins, 226, 1 electronic absorption spectroscopy of nonheme iron proteins, 226, 33 cobalt as probe and label of proteins, 226, 52 biochemical and spectroscopic probes of mercury(ii) coordination environments in proteins, 226, 71 low-temperature optical spectroscopy metalloprotein structure and dynamics, 226, 97 nanosecond transient absorption spectroscopy, 226, 119 nanosecond time-resolved absorption and polarization dichroism spectroscopies, 226, 147 real-time spectroscopic techniques for probing conformational dynamics of heme proteins, 226, 177 variable-temperature magnetic circular dichroism, 226, 199 linear dichroism, 226, 232 infrared spectroscopy, 226, 259 Fourier transform infrared spectroscopy, 226, 289 infrared circular dichroism, 226, 306 Raman and resonance Raman spectroscopy, 226, 319 protein structure from ultraviolet resonance Raman spectroscopy, 226, 374 single-crystal micro-Raman spectroscopy, 226, 397 nanosecond time-resolved resonance Raman spectroscopy, 226, 409 techniques for obtaining resonance Raman spectra of metalloproteins, 226, 431 Raman optical activity, 226, 470 surface-enhanced resonance Raman scattering, 226, 482 luminescence... 

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