Transmission FTIR spectroscopy

Transmission Fourier Transform Infrared Spectroscopy. The most straightforward method for the acquisition of in spectra of surface layers is standard transmission spectroscopy (35,36). This approach can only be used for samples which are partially in transparent or which can be diluted with an in transparent medium such as KBr and pressed into a transmissive pellet. The extent to which the in spectral region (typically ca 600 4000 cm ) is available for study depends on the in absorption characteristics of the soHd support material. Transmission ftir spectroscopy is most often used to study surface species on metal oxides. These soHds leave reasonably large spectral windows within which the spectral behavior of the surface species can be viewed. 

Transmission FTIR spectroscopy may be combined with a number of other experimental techniques such as, e.g., temperature-programmed reduction (TPR), oxidation (TPO) or desorption (TPD) of probes monitored by, e.g., frequency response (FR) spectroscopy (see also Sect. 4.2), electron spin resonance (ESR) spectroscopy, etc. 

The formation of Ru(I)(CO)3 after activation of [Ru(NH3)g] in mordenite or in a deep-bed calcined La-Y zeolite under CO atmosphere at T<373 K was suggested through transmission FTIR spectroscopy in a contribution to this field of research by Schoonheydt et al. [619]. These authors observed bands at 2055,2005 and 1960 cm which were ascribable to Ru(I)(CO)3. However, they did not exclude the possibility that the spectral features could originate from a mixture of monocarbonyls (2005 and 1960 cm ) and dicarbonyls (2055 cm" ). 

Curing of epoxy resin with GMAEVC was quantitatively analyzed by transmission FTIR spectroscopy using a Perkin Elmer FTIR system 2000 model, equipped with a conventional TGS detector. Samples were prepared by casting a thin film of resin onto a sodium chloride plate and placed in a heating cell in the spectrometer to carry out the reaction from 100°C to 170°C at a heating rate of 2°C/min. The temperature of the heated cell was monitored with a DigiSense temperature controller from the Cole Parmer Co. The FTIR spectra were collected at different temperatures and compared to the FTIR spectra of fully cured samples prepared in an oven to confirm the presence of polymerization products. 

Another illustrative example of the application of FTIR spectroscopy to problems of interest in adhesion science is provided by the work of Taylor and Boerio on plasma polymerized silica-like films as primers for structural adhesive bonding [15]. Mostly these films have been deposited in a microwave reactor using hexamethyldisiloxane (HMDSO) as monomer and oxygen as the carrier gas. Transmission FTIR spectra of HMDSO monomer were characterized by strong... 

In one other example, Raman spectroscopy was employed along with FTIR spectroscopy, XPS, elemental analysis, TGA, SEM and transmission electron microscopy (TEM) to follow the compositional and structure variations of polymethylsilsesquioxane samples pyrolysed at different temperatures in an atmosphere of nitrogen [56]. At 900°C the main product was silica, with formation too of some silica oxycarbide and amorphous carbon, with Raman spectroscopy showing complementary evidence for presence of both the minor species. 

Transmission Fourier transform infrared (FTIR) spectroscopy, 24 72, 110 Transmission liquid cells, types of,... 

We report here on the structure and gas transport properties of asymmetric membranes created by the Langmuir-Blodgett deposition of ultra-thin polymeric lipid films on porous supports. Transmission and grazing angle FTIR spectroscopy provide a measure of the level of molecular order in the n-alkyl side-chains of the polymeric lipid. The level of orientational order was monitored as a function of the temperature. Gas permeation studies as a function of membrane temperature are correlated to the FTIR results. 

FTIR spectroscopy has become a standard technique for investigating Idle structure and level of orientational order of ultrathin films, that is, films in the submicron range (2.5 to 500 nm) (9). By combining transmission spectroscopy with infrared reflection-absorption spectroscopy (this technique is also referred to as grazing incidence reflection), the orientation of the functional groups of the molecules in the film can be investigated. These measurements are nondestructive to the film and can be conducted at a range of temperatures and pressures. 

Reaction between LB films of Cd arachidate and ground state atomic oxygen, 0(3P), was investigated at various temperatures using FTIR spectroscopy [55,56]. Intensity of the CH2 stretching infrared band was monitored in a transmission mode and was found to decrease in the course of the reaction due to disappearance of the CH2 groups. 

Fig. 1. (a) THz absorption spectra from Kemp et al. [38]. (b) Comparison study of transmission spectra of RDX using THz-TDS and Fourier Transform Infrared (FTIR) spectroscopy with data from Kemp et al. and Huang et al [39]. The dashed line is RDX from Kemp et al. The other curves are from Huang et al., where the bottom curve is RDX measured by THz-TDS, the solid curve is RDX measured by FTIR, and the top curve... 

FTIR Spectroscopy. Infrared spectra were recorded on a Perkin Elmer Spectrum One FTIR spectrometer equipped with a Deuterated Triglycine Sulfate (DTGS) detector and KBr optics. Data collection was performed at 4 cm-1 spectral resolution in the region of 4000-450 cm-1 and averaged over 5 scans. All samples were measured in transmission mode. 

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