Infrared spectroscopy techniques

Adsorption of TU on active and passive iron electrodes was studied by Bockris et al. using radiotracer and Fourier Transform Infrared Spectroscopy techniques. The high values of AG° (the standard states 0° = 0.582 and c° = 1 mol T ) equal to -17.20 kJ/mol and -18.98 kJ/mol have been obtained for the active and passive iron electrodes, respectively. They are markedly higher than those obtained for other metals (Table 1). 

Whitacre, E. et al., Predictive analysis of cocoa procyanidins using near-infrared spectroscopy techniques, J. Food Scl, 68, 2618, 2003. 

Corrosivity of used oils. The classical determination of TBN and TAN involves a titrimetric procedure, whereby the oil sample is dissolved in a particular solvent system and neutralized by strong acid or strong base (ASTM D664 or 2896), equivalent to (IP 171 or 276). TBN and TAN values do not correlate with corrosivity and the titrimetric analysis has a very limited ability to differentiate between acids of varying strengths. A quantitative differential infrared spectroscopy technique used to monitor the neutralization reaction is more meaningful, since the technique applies to reactions in hydrocarbon solvents. The classical reaction between corrosive acids and hard-core RMs results in formation of the metal salt of the acid and carbonic acid ... 

Composition - Each crude-oil field has a different composition, that can be established by a combination of gas-chromatography, fluorescence-spectroscopy, and infrared-spectroscopy techniques, and that may be used. 

Vaccari G, Dosi E, Campi A L, Gonzalez-Vara A, Matteuzi D, Mantovani G (1994). A near infrared spectroscopy technique for the control of fermentation processes an application to lactic acid fermentation. Biotechnol. Bioengin. 43 913-917. 

FTIR Fourier transform infrared spectroscopy (technique useful in identifying and analyzing various unknown compounds, such as environmental pollutants) GC Gas chromatography (most commonly used analytical technique for organics) GC/MS Gas chromatography/mass spectrometry (technique based on chromatographic separation, followed by chemical or electron-impact ionization and identification of the mass spectra of the ionized fragments)... 

Special thanks to Tomas Vazquez to teach and pass on to us his enthusiasm for the infrared spectroscopy techniques. The authors also thank the support by the MICINN (Ministerio de... 

Infrared Spectroscopy Techniques in the Characterization of SOFC Functional Ceramics... 

Fourier transform infrared spectroscopy (FTIR) has been widely used for in situ analysis of adsorbed species and surface reactions. Infrared spectroscopy techniques have being used for the characterization of solid oxide fuel cells (SOFCs). FTIR is utilized to identify the structure of the SOFC electrode and electrolyte surface (Resini et al., 2009 Guo et al., 2010). Liu and co-workers (Liu et al., 2002) were pioneers in the in situ surface characterization by FTIR under SOFC operating conditions. 

This book chapter reviews how powerful infrared spectroscopy techniques play a fundamental role in the novel synthesis approaches developed during the last 5 years (2007 - 2011) by this research group. Synthesized high p>erformance cathode powders had their features investigated using different materials characterization techniques, such as Fourier Transform Infrared Sp>ectroscopy (FTIK), FAR and MlD-lnfrared spectroscopy. 

Infrared spectroscopy techniques applied in the SOFC research... 

A control technique based on high-frequency pressure measurements was developed and implemented to avoid hydrodynamic instabilities in continuous olefin slurry-loop reactors [ 186]. The obtained high-frequency pressure patterns are compared to typical process responses and then used to classify the status of the plant operation. The idea is that pressure fluctuations that do not follow the standard pattern indicate some sort of process instabiUty. When hydrodynamic instabilities are detected, monomer flow rates and/or reactor temperatures are manipulated to reduce the polymer density and the reaction rates and reduce the risks of plant shutdown. Similar procedures can be used for detection and correction of abnormal plant operation in suspension [ 187] and emulsion [188] polymerizations with the help of Raman and near infrared spectroscopy techniques. 

To understand that spectral information may be obtained from combination infrared spectroscopy techniques. 

It has been demonstrated that there is a direct relationship between the fiber mechanical properties and the molecular orientation (Figure 1). A similar relationship exists between the processing conditions, molecular orientation and mechanical properties. It has been shown that a combination of optical birefringence and the infrared spectroscopy techniques can be used for the measurement of molecular orientation. The results show that for a set of fiber samples, the 841 cm" infrared peak can be confidently used for the estimation of crystalline orientation averages. The 973 cm" peak can be separated using curve fitting procedures into 972 and 974 cm" components and the latter component can be used to estimate the amorphous orientation averages. 

The basic transmission infrared spectroscopy technique has been a workhorse for chemical analysis for many years. As computers and computing techniques became more advanced (FTIR) spectrometers were developed. The introduction of FTIR revolutionised infrared (IR) spectroscopy because for the first time weak signals could be cleared of noise thanks to co-addition and Fourier analysis of many scans. 

The preparation of natural rubber-gra/t-methyl methacrylic acid has been reported by Lenka and coworkers. The vanadium ion was used as an initiator, which initiated the creation of free radicals on the backbone of natural rubber and this increased the interaction between the natural rubber and the methyl methacrylate surfaces. The coordination complexes derived from the acetylacetonate of Mn(III) ions could also be used as an initiator to form the natural rubber-gra/t-methyl methacrylic acid. Under different conditions, silver ions could be used as a catalyst to produce natural rubber-gra/t-methyl methacrylic acid with different concentrations of methyl methacrylic acid monomers, and potassium peroxydisulfate as an initiator. Consequently, these methods were successful in the preparation of compatible blended natural rubber and methyl methacrylic acid by graft copolymerization. This compatibility was confirmed by nuclear magnetic resonance and infrared spectroscopy techniques. The interaction between natural rubber and methyl methacrylic acid was significantly increased and was useful for further blending with other polyacrylate molecules or different polymer types. 

Beginning in 1968,Tasumi and Krimm (103) undertook a series of experiments using a mixed crystal infrared spectroscopy technique. Mixed single crystals of protonated and deuterated polymer were made by precipitation from dilute solution. The characteristic crystal field splitting in the infrared spectrum was measured and analyzed to determine the relative locations of the chain stems of one molecule, usually the deuterated portion, in the crystal lattice. The main experiments involved blending protonated and deuterated polyethylenes (104-106). 

Toward filling these voids, we have developed several fast thermolysis/Fourier transform infrared spectroscopy techniques that permit near real-time studies of energetic materials heated at 70-400 C/sec under selected pressures in the 1-1000 psi range. These techniques are described in the companion article for this Institute. 

Also, literature reports new biodegradable poly(ethylene oxide)/cellulose, poly(ethylene oxide)/cellulose acetate, poly(ethylene oxide)/carboxymethyl cellulose, and poly(ethylene oxide)/cellulose ether blends obtained by solution casting and investigated by differential scanning calorimetry, temperature-modulated differential scanning calorimetry, and infrared spectroscopy techniques [134]. These studies indicate... 

G. Horlick, R. H. Hall, and W. K. Yuen, Atomic emission spectrochemical measurements with a Fourier transform spectrometer, in Fourier Transform Infrared Spectroscopy Techniques Using Fourier Transform Interferometry, J. R. Ferraro and L. J. Basile, Eds., Academic Press, New York, 1982, Vol. 3, p. 37. 

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