Fourier transform infra-red spectroscopy FTIR

Such a theoretical model has been quite successfully checked by Fourier transform infra-red spectroscopy (FTIR) on polystyrene [11,12]. Indeed, the FTIR spectrum of polystyrene contains vibrational lines associated with out-of-plane modes of the phenyl ring, whose position depends on the gauche or trans conformation of the main-chain C - C bonds. By recording FTIR spectra during sample stretching, it is possible to determine the amount of gauche or trans conformation as a function of strain. 

In this paper, plasma fluorinated PMDA-ODA films and PTFE were studied to understand beam interactions with the polymers as a function of irradiation time. X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM) and RBS were used to determine changes induced in the polymers by irradiation. 

The limitations in applying conventional infra-red spectroscopy to biochemical problems have been largely circumvented by the use of a variant of the technique called Fourier Transform Infra-Red spectroscopy (FTIR). In this technique, the incident... 

In situ Fourier transform infra-red spectroscopy (FTIR) can be used to trace the appearance of surface-active groups on the polymer surface, and to characterize the insertion of counter-ions as a function of the doping level. 

All 200 MHz 1h NMR and 360 MHz H NMR spectra were recorded on a Bruker WP-200 and Bruker WP-360 spectrometer respectively using DISNMR software. Samples were dissolved in CDCI3, and were referenced downfield to tetramethylsilane (TMS) at 5 0.00. Fourier transform infra-red spectroscopy (FTIR) was performed on a Digilab FTS-60 instrument using either KBr or NaCl windows. Typically 64 scans were taken for each sample at a resolution of 2 cm". ... 

Tensile extensibility is a particularly sensitive measure of the extent of weathering. Alternatively, the development of carbonyl functionalities (>C=0) or other spectral changes in samples determined in Fourier Transform Infra-Red Spectroscopy, FTIR, might be used to assess degradation, hi PE (Andrady et al., 1993b), the development of the carbonyl functionalities correlates well with the decrease in extensibility. Plastics such as PVC, PC, or PS (Ghaffar et al., 1976) turn yellow on photodegradation. Surface... 

Fourier transformed infra red spectroscopy (FTIR) Measurement technique whereby infra-red absorption spectra of materials are analyzed by mathematical Fourier transform... 

Several experimental techniques can be used to study transport phenomena in polymers nuclear magnetic resonance imagiug (NMR), UV spectrophotometer, gas chromatography/flame ionization detector (GCMD), high-performance liquid chromatography (HPLC), laser interferometry, gravimetric method and Fourier Transform Infra-Red spectroscopy (FTIR). 

The Fourier Transform Infra-Red spectroscopy (FTIR) technique is a valuable method for investigating the kinetics of sorption of organic molecules in polymers, hi further works (Safa and Abbes, 2002 Safa et al., 2007 Zaki et al. 2009), we have used such method to study the sorption rate of different esters by polypropylene. The ester function is characterized by absorption band in regions where the polypropylene does not absorb. The sorption can be evaluated by the ratio of the carbonyl ester (CO) band area at 1747 cm to the area of a characteristic peak of the PP at 841 cm used as a reference band. The polymer samples are cut-out in thin films of 50 pm thickness by using a microtome. These films are then put on a support adapted for the spectroscopic analysis. Figure 5 shows FTIR spectra of a polypropylene sample after contact with 5000 ppm of amyl acetate solution at 23°C after 5 hours, 4 days and 15 days of immersion. The absorption characteristic band of esters at 1747 cm and its growth is clearly observed. 

The recrystallization of S-layer proteins at phosphatidylethanolamine monolayers on aqueous subphases was also studied on a mesoscopic scale by dual label fluorescence microscopy and Fourier-Transform-Infra-Red spectroscopy (FTIR) [87], It was shown that the phase state of the lipid exerts a marked influence on the protein crystallization. When the surface monolayer was in the phase separated state between the fluid and crystalline phases, the S-layer protein was preferentially absorbed at the boundary line between the two coexisting phases and crystallization proceeded underneath the crystalline phase. Crystal growth was much slower under the fluid lipid and the entire interface was overgrown only after prolonged protein incubation. In turn, as indicated by characteristic frequency shifts of the methylene stretch vibrations on the hpids, protein crystallization affected the order of the alkane chains and drove the fluid lipid into a state of higher order. It was also found that the protein did not interpenetrate the lipid monolayer as confirmed by X-ray reflectivity studies [85]. 

More frequently than chemical techniques, the spectroscopic methods of analysis are used for the determination of polymer chemical composition. Among these techniques the use of infrared (IR) absorption spectra as fingerprints for polymer identification is probably the most common. The IR absorption is produced tjy the transition of the molecules from one vibrational quantum state into another, and most polymers generate characteristic spectra. Large databases containing polymer spectra (typically obtained using Fourier transform infra-red spectroscopy or FTIR) are available, and modern instruments have efficient search routines for polymer identification based on matching an unknown spectrum with those from the library. For specific polymers, the IR spectra can reveal even some subtle composition characteristics such as interactions between polymer molecules in polymeric blends. 

GC-Fourier transform infra-red (GC-FTIR) spectroscopy is less frequently used than GC-MS, but involves a similar principle in which the outlet from the column is coupled to an infra-red spectrophotometer. The technique currently suffers from a lack of library spectra, as the IR spectra taken in the vapour phase can be subtly different from condensed-phase spectra or spectra collected using the well-established KBr disc method. 

GPC Gel Permeation Chromatography FTIR Fourier Transform Infra Red Spectroscopy... 

Attenuated total reflection-Fourier transform infra-red (ATR-FTIR) spectroscopy was used to determine the concentration of a chemical additive (cationic polyacrylamide resin) within a pulp fibre. The depth distribution of the additive was determined by sputter etching the fibre surface. The obtained profile was compared qualitatively with that obtained by the variable-angle ATR-FTIR depth profiling method. Most of the additive was located at the surface, with some distributed within the fibre. It is concluded that the method can be used to clarify the distribution of other paper additives within a pulp fibre, and that it can be applied to depth profiling of minor components within a solid material. 21 refs. 

Figure 2 Pore Size Distributions of Raw and Treated OFA 3.2 FTIR (Fourier Transform infra-red) Spectroscopy...

AAm Acrylamide FTIR Fourier transform infra-red spectroscopy ... 

Hyphenated TLC techniques. TLC has been coupled with other instrumental techniques to aid in the detection, qualitative identification and, occasionally, quantitation of separated samples, and these include the coupling of TLC with high-pressure liquid chromatography (HPLC/TLC), with Fourier transform infra-red (TLC/FTIR), with mass spectrometry (TLC/ MS), with nuclear magnetic resonance (TLC/NMR) and with Raman spectroscopy (TLC/RS). These techniques have been extensively reviewed by Busch (1996) and by Somsen, Morden and Wilson (1995). The chemistry of oils and fats and their TLC separation has been so well established that they seldom necessitate the use of these coupling techniques for their identification, although these techniques have been used for phospholipid detection. Kushi and Handa (1985) have used TLC in combination with secondary ion mass spectrometry for the analysis of lipids. Fast atom bombardment (FAB) has been used to detect the molecular species of phosphatidylcholine on silica based on the molecular ion obtained by mass spectrometry (Busch et al, 1990). 

Figure 5.10 Scheme for characterization of cyclic fatty acid monomers (CFAMs) from heated vegetable oils. HPLC = high-pressure liquid chromatography GC = gas chromatography FTIR = Fourier transform infra-red (spectroscopy) MS = mass spectrometry DMOX = dismethyloxazoline. 

Fourier Transform Infra-Red Spectroscopy The internal tetrahedra and external linkage of the zeolites formed are identified and confirmed by FTIR. The IR spectra data are taken from Ojha et al. (2004) and shown in Table 6.8. 

The thermal decomposition of halogenated and non-halogenated unsaturated polyester resins (UPR s), fire retarded by zinc hydroxystannate (ZHS) and cross-linked with styrene, has been investigated by thermogravimetiy (TG) and TG coupled on-line with Fourier transform infra red spectroscopy (TG-FTIR) or mass spectroscopy (TG-... 

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