Fourier transform infra-red spectroscopy

Fourier Transform Infra Red Spectroscopy, Arrhenius plots of rate vs. temperature of a membrane-linked phenomenon) that biological membranes from nonhibemat-ing or cold acclimated animals show a phase transition around 12 °C to 17 °C. Thus, at useful cold storage temperatures, it is expected that the plasma membrane and membranes of the cellular organelles will be mostly in a gel or solid state. 

Because chemical and structural properties of natural and artificial gems are very similar in this case, the possibilities of Raman and LIBS methods are rather limited. It was found that another laser-based techniques could be very effective for rapid spectroscopic discrimination between natural and synthetic emeralds, rubies, and alexandrite (Armstrong et al. 2000a,b). The first one is DRIFTS (Diffuse Reflectance Fourier Transformed Infra-Red Spectroscopy)... 

W.Hemes, Capillary Gas Chromatography-Fourier Transform Infra Red Spectroscopy-Applications, Huethig, 1987. 

DSC is increasingly being applied to the study of epoxy resin cure in combination with other analytical methods such as nuclear magnetic resonance and Fourier transform infra-red spectroscopy, chromatographic methods, and dynamic mechanical or dielectric studies. It is probably as part of such combined investigations that DSC can be used most effectively in basic research, and in quality control and assessment. 

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. 

Some very important surface properties of solids can be properly characterized only by certain wet chemical techniques, some of which are currently under rapid improvement. Studies of adsorption from solution allow determination of the surface density of adsorbing sites, and the characterization of the surface forces involved (the energy of dispersion forces, the strength of acidic or basic sites and the surface density of coul-ombic charge). Adsorption studies can now be extended with some newer spectroscopic tools (Fourier-transform infra-red spectroscopy, laser Raman spectroscopy, and solid NMR spectroscopy), as well as convenient modern versions of older techniques (Doppler electrophoresis, flow microcalorimetry, and automated ellipsometry). 

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. 

Koenig JL (1981) Fourier transform infra-red spectroscopy of chemical systems. Acc Chem Res 14 171-178... 

The assistance of several postdoctoral and doctoral fellows must be acknowledged in particular, Dr. Patrick McCarthy for his major contribution to the chapter on techniques for measuring lipid peroxidation Dr. Parves Haris for his assistance and expertise in the preparation of the section on Fourier Transform Infra Red Spectroscopy, Mr. George Paganga for the section on the preparation of low density lipoproteins and Dr. Paul Eggleton for the preparation of the section on the nitro blue tetrazolium assay. 

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... 

The photooxidation rates of nylon polymers have been monitored using Fourier Transform Infra-red spectroscopy. Norrish type-II reactions of carbonyl groups were considered to be the most important process. Another group of workers have studied the photooxidations rates of a nylon 6- polypropylene glycol copolymerIn this case polyether sequences are the major source of free radical attack resulting in high levels of hydroperoxides. Irradiation of nylon and polyester fibres with an excimer laser resulted in... 

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. 

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. 

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

SNIFTRS Subtractively Interfacial Fourier Transform Infra-Red Spectroscopy PM-FT-IRRAS Polarization Modulated Fourier Transform Infra-Red Reflection Absorption Spectroscopy... 

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". ... 

Bicchi C, Rubiolo P, Frattini C (1989b) Capillary gas chromatography-Fourier transform infra-red spectroscopy of pyrrolizidine alkaloids of Senecio inaequidens DC. J Chromatogr 473 161-170... 

Fourier transform infra red spectroscopy was used to study the cure reaction and reaction kinetics of a commercial phenolic resin, using IR spectra in the absorbance mode. It was found that below 140 deg. centigrade that the... 

Blends of polyethylene terephthalate and linear low-density polyethylene were compatibilised using diethylmaleate grafted polyethylene, and characterised using Fourier transform infra-red spectroscopy, thermogravimetric analysis and scanning electron microscopy. Interactions between the components in the blends were observed, which affected the glycol sequences of the polyester and also improved the thermal oxidative stability of the blends. The introduction of the compatibiliser resulted in a particle size reduction of the dispersed phase and better adhesion between the phase and the matrix. 15 refs. 

The condensation grafting of polyethylenimine (PEI) onto poly(acrylamide-co-acrylic acid) (PAM-co-AA) was studied. Fourier transform infra-red spectroscopy was... 

The nature of the complexes formed by the interactions between polyacrylic acid (PAA) andpolymethacrylic acid (PMAA) and with poly(4-vinylpyridine) and poly(2-vinylpyridine) in ethanol/water solution was studied using Fourier transform infra-red spectroscopy and x-ray photoelectron spectroscopy. The PMAA complexes involved hydrogen-bonding interactions, whilst there was evidence of ionic interactions in the PAA complexes. This difference in the behaviour between the complexes is attributed to the higher acidity of PAA compared with that of PMAA. 23 refs. 

No.14, July 1993, p.2934-45 FOURIER TRANSFORM INFRA-RED SPECTROSCOPY ON THE THERMOOXIDATIVE DEGRADATION OF POLYBENZEVHD AZOLE AND OF A POLYBENZEVHDAZOLE/POLYETHERIMIDE BLEND... 

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

---