Phase characterization using FTIR

The goal of our investigations was to characterise the morphology of the sample, and to determine the size and location of the PTFE and silicone oil phases by different methods [46,47], For phase characterization using Raman microscopy, no special sample preparation was necessary. For FTIR imaging, microtomed sections (5 pm in thickness) had to be prepared by cutting the sample with a diamond knife at — 80°C ("cryo-microtomy") to prevent smearing and to obtain flat surfaces. 

The nanostructured bimetallic catalysts were characterized using several techniques, and some of the main results are summarized in this section. We first describe the size and composition of the AuPt nanoparticles determined from TEM and DCP-AES analysis. This description is followed by discussion of the phase properties based on XRD results. We further discuss the FTIR provbing of CO adsorption on the bimetallic nanoparticle catalysts. 

All the samples were characterized using conventional methods X-ray diffraction (Rigaku, D-Max IIIB), UV-VIS (Shimadzu 240), FTIR (Perkin-Elmer 1760), EDX (JEOL-5200), SEM (Philips Model 525), Cyclic voltammetry (Rikadenki), DTA-TGA (Dupont, 951), Particle size analyzer (Galai CIS-100), BET surface areas (350-450 m /g). Chemical analysis was obtained by atomic absorption (AAS) after solubilization of the samples in HF-HCl solutions. It was ascertained that the samples were free of any phase impurity and are catalytically active. 

When systems can form multiple anhydrate, hydrate, and solvate phases, the use of infrared spectroscopy can be extremely valuable. For example, depending on the recrystallization solvent, delavirdine mesylate has been found to form two anhydrous phases, two hydrates, an ethanol solvate, and an acetonitrile solvate, as well as six other phases resulting as the products of solid-state transformations of the hydrated and solvated phases [126], In this work, FTIR spectroscopy played an important role in working out the characterization of this system. 

Only a few studies had directly been devoted to the first pm and nm of the hardened concrete s surface using FTIR in Attenuated Total Reflexion (ATR mode), pRaman and XPS technique, respectively. This lack of application is one of the root purposes of this paper prove that the surface of concrete can be characterized with these three spectroscopic techniques just after demoulding, after siloxane post-treatment and after coating with a polyester-polyurethane varnish. pRaman is used to analyze the phase distribution and isolated grains after demoulding and to evaluate posttreatments efficiency. The FTIR and XPS complete the Raman results about the presence of organic compounds and confirm the study s methodology. 

Abstract— Thermal analysis of hydroxyapatite formation through dry mechanochemical method has heen stndied. The calcium phosphate was synthesized using calcinm hydroxide and di-ammonium hydrogen phosphate as the precnrsors. The ball milling of 1/6 ball-powder mass ratio was employed on mixtures of calcium hydroxide and di-ammoninm hydrogen phosphate in three different speeds 170, 270 and 370 rpm for 15 h. As ball-milled powders were then sintered at 1150, 1250 and 1350°C for 2 h, then subjected to TGA, XRD and FTIR for phase characterization. Calcium phosphates with ammonium are phases of the material. The ammonium is trace of phosphorus precursor. Choosing condition of the process and type of precursors determines type of reactions and its products. 

Studies of the adsorbed odCB phase by C NMR MAS and FTIR spectroscopies were carried out (ref.4). They evidence the occurence of protonated odCB species at the surface and their interaction with Bronsted sites of the catalyst. These features are confirmed by the very good application of the Hammett equation to the isomerisation of p-substituted bromobenzenes (Fig. la). This equation takes the form, log (rate) = constant + trp, in which charge transfer between the initial and the transition states is occuring, the use of cr+is prefered (ref. 16). 

More recently, pyrolysis GC, ESCA, and FTIR have been used to characterize the surface of bonded layers. The reason for the intense interest is the fact that there are significant differences between bonded phases manufactured by different companies, and these investigators hope to find out why. One recent study15 analyzed the decomposition products produced by the reaction of bonded reverse phases with HF, and it was able to determine the type of reaction (monofunctional or polyfunctional), the extent of end capping, and the distribution of lengths of alkyl groups. Some of the results of the study are summarized in Table 7. Such results help explain the differences between bonded phases manufactured by different companies. 

The effects of substrate temperature (Ts b) on cubic boron nitride (c-BN) films synthesized using magnetron sputtering were studied. Fourier transform infrared (FTIR) spectroscopy. X-ray photoelectron spectroscopy (XPS) were employed to characterize the structure and composition of the films. It is found that Ts , plays a crucial role on the formation of cubic phase, and an appropriate T, , can lead to a high content. A tentative explanation on the mechanism of such Ts b effects is reported with the most details. 

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