FTIR emission spectroscopy

Pibel C D, Sirota E, Brenner J and Dai H L 1998 Nanosecond time-resolved FTIR emission spectroscopy monitoring the energy distribution of highly vibrationally excited molecules during collisional deactivation J. Chem. Phys. 108 1297-300... 

The following sections are not intended to give an exhaustive account of the application of time-resolved FTIR emission spectroscopy, but highlight particular problem areas in chemical physics to which the technique is particularly suited and focus on photochemical reactions, and results which have emerged since the previous reviews on the subject [26,27]. 

When the spectral characteristics of the source itself are of primary interest, dispersive or ftir spectrometers are readily adapted to emission spectroscopy. Commercial instruments usually have a port that can accept an input beam without disturbing the usual source optics. Infrared emission spectroscopy at ambient or only moderately elevated temperatures has the advantage that no sample preparation is necessary. It is particularly applicable to opaque and highly scattering samples, anodized and painted surfaces, polymer films, and atmospheric species (135). The Voyager interferometric spectrometer (IRIS) spectra from the outer planets demonstrated the analytical capabilities of ftir emission spectroscopy. As an example of industrial... 

FTIR EMISSION SPECTROSCOPY APPLIED TO POLYMER DEGRADATION... 

Fig. 1.24. Schematic diagram of sampling arrangement for FTIR emission spectroscopy. After Rintoul et ai [109]. From L. Rintoul et al. Analyst 123, 571-577 (1998). Reproduced by permission of The Royal Society of Chemistry.

Table 1.23. Main characteristics of FTIR emission spectroscopy...

TG-FTIR emission spectroscopy may be used to study the chemical nature of the surface of the sample. 

TG-FTIR has been used to study talc-Irganox 1010 interactions [371]. According to the nature of talc three states (free, surface and adsorbed) of Irganox 1010 molecules could be identified in the presence of the filler. TG-FTIR has also been employed for the study of zinc stearate [372], of wood as a filler to thermoset plastics as well as for out-gassing, which leads to bubbles in painted plastic surfaces and potentially toxic gases. Ezrin et al. [255] have reported troubleshooting by means of TG and (off-line) FUR. For other TG-FTIR and TG-MS applications, cfr. ref. [373]. TG-FTIR emission spectroscopy can be used to study the chemical nature of the surface of the sample. Mullens et al. [359] have recently reviewed TG-FTIR applications. 

Woodbridge, E.I., T.R. Fletcher, and S.R. Leone (1988), Photofragmentation of acetone at 193 nm Rotational- and vibrational-state distributions of the CO fragment by time-resolved FTIR emission spectroscopy, J. Phys. Chem., 92, 5387-5393. 

Vibrational Spectroscopy. Infrared absorption spectra may be obtained using convention IR or FTIR instrumentation the catalyst may be present as a compressed disk, allowing transmission spectroscopy. If the surface area is high, there can be enough chemisorbed species for their spectra to be recorded. This approach is widely used to follow actual catalyzed reactions see, for example. Refs. 26 (metal oxide catalysts) and 27 (zeolitic catalysts). Diffuse reflectance infrared reflection spectroscopy (DRIFT S) may be used on films [e.g.. Ref. 28—Si02 films on Mo(llO)]. Laser Raman spectroscopy (e.g.. Refs. 29, 30) and infrared emission spectroscopy may give greater detail [31]. 

It is becoming more and more desirable for the analytical chemist to move away from the laboratory and iato the field via ia-field instmments and remote, poiat of use, measurements. As a result, process analytical chemistry has undergone an offensive thmst ia regard to problem solviag capabihty (77—79). In situ analysis enables the study of key process parameters for the purpose of definition and subsequent optimization. On-line analysis capabihty has already been extended to gc, Ic, ms, and ftir techniques as well as to icp-emission spectroscopy, flow iajection analysis, and near iafrared spectrophotometry (80). 

The characterization of graphene often involves several techniques in conjunction in order to build up a complete picture of the material. The techniques typically include electron microscopy, Raman spectroscopy, X-ray photo-emission spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and thermal-gravimetric analysis (TGA). 

Fourier transform methods have revolutionized many fields in physics and chemistry, and applications of the technique are to be found in such diverse areas as radio astronomy [52], nuclear magnetic resonance spectroscopy [53], mass spectroscopy [54], and optical absorption/emission spectroscopy from the far-infrared to the ultraviolet [55-57]. These applications are reviewed in several excellent sources [1, 54,58], and this section simply aims to describe the fundamental principles of FTIR spectroscopy. A more theoretical development of Fourier transform techniques is given in several texts [59-61], and the interested reader is referred to these for details. 

Microbial transformations of DOM were also studied by incubation experiments. The DOM extracted from maize straw and forest floors was incubated for 90 days and samples taken before and after incubation were analyzed by Py-FIMS and complementary UV absorbance, fluorescence emission spectroscopy, FTIR-spectroscopy, 1H NMR spectroscopy, and 13C natural abundance (Kalbitz et al., 2003). The Py-FI mass spectra showed increases in the proportions of phenols and lignin monomers at the expense of lignin dimers and alkylaromatics during... 

Chemical vapor deposition (CVD) using TiC was used to prepare Ti/Si02, Ti/MCM-41, and Ti/MCM-48 catalysts. These catalysts were characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, nitrogen adsorption, and were used to catalyze the epoxidation of propylene to propylene oxide (PO) with in situ prepared ethylbenzene hydroperoxide (EBHP). CVD time and CVD temperature affected the catalyst performance significantly. The optimum temperature range was 800-900 °C, and the optimum deposition time was 2.5-3 h. The maximum PO yields obtained in a batch reactor were 87.2, 94.3, and 88.8% for Ti/Si02, Ti/ MCM-41, and Ti/MCM-48, respectively. Ti/MCM-41 had higher titanium... 

Products of Laser Ablation. The volatile products of laser ablation of a Kapton film were measured with quadrupole mass spectrometry and with emission spectroscopy using the same Kapton samples and experimental setup as for the DRIFT measurements. In the mass spectra C2H2, HCN, CO, C02, C4H2, and C6H2 could be detected, while the emission spectra showed the C2 and CN emission lines. The chemical species in the mass spectra were assigned according to the Refs [61] and [162], which used gas-phase FTIR and GC-MS for the assignment of the decomposition products. 

Analysis of FTIR spectra of the ionomer(Figures 3 and 4) was also informative about the structure. It was reported previously that IR absorption bands at 1893 cm" and 1905 cm"l were characteristics of 4-methylstyrene (of > 50) and 4-bromomethyl styrene (of Exxpro elastomer, Figure 5). Such absorption bands were not found in the FTIR spectra of the above ionomers. However, new absorption peaks, characteristics of the quaternary phosphonium salts, at 1580, 1100, 100, 670-730 cm" were observed. The presence of both phosphorous and boron in the above ionomers was also confirmed in terms of the elemental analysis data, collected from the inductively coupled plasma/atomic emission spectroscopy(ICP/AES) technique. These results were in good agreement with the expected convertion of the respective phosphonium salts. 

Framework and Surfaces Since compositions and structures are very diverse, surface and framework properties are also extremely varied. In terms of compositions, coordination, and chemical environments, several methods are particularly informative for the characterization of nanoporous solids, such as nuclear magnetic resonance methods (NMR), UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray absorption spectroscopies, x-ray photoelectron emission spectroscopy (XPS), and electron paramagnetic resonance (EPR) (4, 6). Among them, sohd state NMR techniques arc largely employed and will be briefly described in the following. 

Basically, there are two categories of FTIR spectroscopies reflection and nonreflection techniques [38], The latter class comprises either acoustic detection or emission from the sample itself. The techniques recognized here are photoacoustic spectroscopy (PAS), emission spectroscopy (EMS), and photothermal beam deflection spectroscopy (PBDS). These techniques will not be considered further in this chapter. The reader is referred to the literature [39-42], For adhesion studies the reflection techniques (SRIRS) are more important. The major classes of sampling techniques in SRIRS are ... 

FTIR photoacoustic spectroscopy (PAS) has advantages relative to conventional IR techniques (transmission, reflection and emission) because it is non-destructive, does not involve sample preparation and can probe samples with compositional gradients and layers. The theory, instrumentation, methods and applications of FTIR-PAS are discussed and results are presented on several polymer analyses based on FTIR-PAS. 4 refs. USA... 

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