Infrared micro-spectroscopy crystals

Infrared Micro-Spectroscopy of Molecules In Single Crystals or Powders of Zeolites... 

Three different ZSM-5 crystal types have been studied by synchrotron infrared micro-spectroscopy, namely parent zeolite (ZSM-5-P), mildly treated zeolite (ZSM-5-MT) and severely treated zeolite (ZSM-5-ST). The goal is to compare the influence of different dealumination conditions on the molecular diffusion and reactivity of individual ZSM-5 crystals. Synchrotron-based IR micro-spectroscopy [34] was used in combination with pyridine adsorption. Pyridine, having a molecular dimension of 0.57 nm, is able to diffuse throughout the micropore system of ZSM-5 and allows the detection of all acidic sites present within the zeolite material [35]. The sorption of pyridine was introduced at room temperature and the samples were subsequently heated up to 573 K and 673 K. The Bronsted acid sites, giving rise to IR spectra of adsorbed pyridine at around 1545 cm , allow the visualization of differences in the nature and strength of the acid sites in the zeolite crystals under investigation. Fig. 4 shows the IR spectra of the adsorbed pyridine collected at room temperature, 573 K and 673 K for the ZSM-5-P, ZSM-5-MT and ZSM-5-ST crystals. 

Isomorphous substitution of boron into the MFI structure to produce [B]ZSM-5 was carried out and investigated via FTIR micro-spectroscopy ( infrared microscopy ) of single crystals by Jansen et al. [308]. Typical bands were observed at 1380 and 905 cm. The integrated band intensity of the 905 cm" band was used as a quantitative measure of the boron content, and the boron distribution in the single crystals was shown to be homogeneous. 

Hu J., Ultra-sensitive chemical vapor detection using micro-cavity photothermal spectroscopy. Opt Express, 18, 22174-22186 (2010). Lin H., Zou Y, and Hu J., Double resonance 1-D photonic crystal cavities for single-molecule mid-infrared photothermal spectroscopy Theory and design. Opt Lett, 37,1304-1206 (2012). 

A rate enhancement effect due to secondary nucleation has been identified in the solution-mediated transformation of the 7-phase of (i)-glutamic acid to its / -phase [82]. In this study, the kinetics of the polymorphic transition were studied using optical microscopy combined with Fourier transform infrared, Raman, and ultraviolet absorption spectroscopies. The crystallization process of n-hexatriacontane was investigated using micro-IR methodology, where it was confirmed that single... 

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... 

These devices are based on the anisotropic absorption of light. Usually molecular crystals exhibit this property and tourmaline is the classical example for this. For practical purposes, however, micro crystals are oriented in polymer sheets. Polymers containing chromophors become after stretching dichroic polarizers. The devices produced in this manner are called polawids. They have found a broad application in many technologies. Their application in spectroscopy is limited to the near ultraviolet and to the visible and near infrared range of the spectrum. In vibrational spectroscopy polaroids are employed as analyzers only for Raman spectroscopy. 

Time-resolved in-situ micro-infrared spectroscopy was applied for the first time by Nowotny et al. [862] on a process occurring in a zeolite single crystal. These authors monitored the thermal decomposition of the template (tripropylamine, TPA) in single crystals of MFI materials with nsi/n i ratios below 1000 (silicalite-1), 122, and 31 (ZSM-5). Bands of the CH stretching modes at 2981, 2943,2882 and 2746 cm and of the CH bending vibrations at 1473 and 1458 cm" were observed. From the presence of the latter two bands the authors concluded that at ambient temperature TPA is rather immobile in the channels of the as-synthesized ZSM-5 crystals. From their measurements they arrived at the conclusions that... 

Fourier transform infrared spectroscopy Micro-flow imaging Poly(dimethylsiloxane) Polymethylsilsesquioxane Quartz crystal microbalance Random sequential adsorption Surface plasmon resonance Total internal reflection fluorescence X-ray photoelectron spectroscopy... 

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