FTIR-ATR Analysis

The infrared spectra in the FTIR-ATR (FTIR, Fourier transform infrared ATR, Attenuated total reflectance) spectra of the compost soil burial tested PBS and biocomposite buried for 60 days were obtained using a FTIR spectrophotometer. A diamond was used as an ATR crystal. The specimens after the compost burial test were analyzed over 525-4000 cm range and the resolution of the spectrum was 4cm. AU spectra were averaged over 32 scans. This analysis was performed at point-to-point contact with a pressure device when analyzing the solid specimens. 

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Thus, a poly isobutylene coating on silver halide optical fiber was used for environmental analysis of chlorinated hydrocarbons in water in an instrument designed for operation in seawater 500 m under the surface (Fig. 9.27). The enrichment membrane concept can be used for FTIR-ATR analysis of liquid and gaseous samples alike. 

On the other hand, it is important to say that chitin-pwlyurethane interaction has an important physical component, since attraction forces as Van der Waals interactions and hydrogen bonds are present at the interface chitin-polyurethane. This aspect could have caused that chitin-polyurethane chemical interaction was not strong enough to be more clearly observed by means of the FTIR-ATR analysis. In addition, chitin was added to the biocomposite in solid form, which limits the achievability of amine and hydroxyl groups of chitin surface due to a steric impediment. Other important aspect to point out is that polyurethane film thickness over the interface chitin-polyurethane could be irregular, which could difficult to reach the chitin-polyurethane interface by infrared light. 

Spectral studies such as Fourier transform infrared/attenuated total reflectance (FTIR/ATR) analysis, solid-state or pulse field gradient (PFG) nuclear magnetic resonance (NMR), x-ray diffraction (XRD) or small angle x-ray scattering (SAXS) analysis, and Raman study are basically the characterization methods for hybrid/ composite membranes. Sometimes, the multiple spectral analyses are necessary to better understand the structure-property relationship for a kind of composite polyelectrolytes. 

Forensic/security analysis 874 Forest-spring encephalitis e265 Free radicals 418 Fructose 256 Fruits e280 FTIR-ATR 819, 821 Fuel cell catalysts 915 materials 932 Fullerenes 56-57, 68 Fusarium sp e303... 

While the condensed phase analysis of the residue (by FTIR-ATR) of PA6 is ongoing, we present the results of TG/ATR for polybutylene terephthalate (PBT)-modihed by a phosphinate FR or nanoparticles (sepiolite) or the combination of phosphinate and nanoparticles. 

Attenuated Total Reflectance FTIR (ATR-FTIRf) is a method that has been applied by a number of workers for the study of protein conformation. ATR has been used for monitoring adsorption of proteins or blood components to sur ces (1,2), and for the structural analysis of proteins dried onto an IRE (thin film) (3,4). It has also been used for exploring the effects of solution conditions on the structure of proteins irreversibly adsorbed to an IRE (5,6,7), and has been shown to be usefel for studying the secondary structure and ligand binding properties of membrane proteins (8,9). 

The feasibility of using FTIR-ATR spectroscopy for qualitative and quantitative analysis was investigated using the three known polymorphs of ganciclovir as a model system.65 Definitive identification of each polymorph was obtained from materials that did not need to be subjected to any sample handling or preparation. Quantitation of mixtures was carried out using a partial least-squares procedure, with mean absolute errors of less than 3% being reported for Form-I and Form-II, and about 6% for Form-Ill. 

The most widely available technique for identifying mainly polymer, but also additives in plastics, is Fourier Transform Infrared (FTIR) spectroscopy. Samples are exposed to infrared light (4000-400 wavelengths per centimetre or cm ) causing chemical bonds to vibrate at specific frequencies, corresponding to particular energies. In the last 5 years, an accessory for FTIR has been developed, which enables non-destructive examination of surfaces and so is ideal for analysis of plastics in museum collections. Attenuated Total Reflection-FTIR (ATR-FTIR) requires samples to be placed on a diamond crystal with a diameter of 2 mm through which the infrared beam is reflected... 

The surface modification was further followed by FTIR (ATR) spectroscopy on a Perkin-Elmer System 2000. Analysis was performed with an internal reflection element (GaAs crystal, 45° incidence angle) with 100 scans co-addition and a resolution of 4 cm . The insoluble, inert PTFE was cut into thin microtome slices between 150-500 nm and analyzed in transmission mode. 

The challenge in FTIR quantitative analysis of polymers is the thickness of the sample. The use of peak ratios standardizes the absorbance signal and eliminates the thiekness variable. Attenuated total reflectanee (ATR) and microscope FTIR were the two methods ehosen to acquire the FTIR spectra. The filler eontent in the polymer was confirmed by ashing. 

Biocomposites are very fascinating materials since they offer characteristics of two or more different materials, in order to have very specific features that would be practically impossible to obtain by every single material of biocomposite. Chitin is an abundant biopolymer obtained from shrimp, insects and some vegetal species. This material is capable to remove some contaminants like fluoride from water. Nevertheless, in order to improve the mechanical characteristics of chitin, in order to be applied in water treatment in real conditions, it must be supported. Polyurethane is a very versatile polymer due to its chemical structure. During its synthesis, interactions between functional groups take place in order to create the urethane group. The synthesis of biocomposite must bear in mind that interaction between compounds is essential to create a mechanical and chemical resistant material. FTIR with ATR analysis was carried out to characterize a biocomposite based on chitin and polyurethane, demonstrating that interaction between them occurs. 

Analysis of FTIR-ATR spectra showed that the biocomposite spectrum was very similar to that of polyurethane. In addition, it is important to point out that main bands of chitin spectrum were at the same wavenumber intervals that those of pxjlyurethane (see Figure 4). 

Products were characterized by Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR), ultraviolet visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), and broadband dielectric/impedance spectroscopy (BDS). New absorption bands were observed corresponding to the conjugated pol5mieric units by FTIR-ATR and UV-Vis spectrophotometric analysis. The influence of concentration of PEDOT-PSS and PEDOT on the composite electrospun nanofibers was studied by EIS. Morphologies of electrospun nanofibers were also investigated by SEM. 

Obtained composite fibers were characterized by FTIR-ATR spectrophotometry, UV-Vis spectrophotometry, EIS, and morphological analysis. 

Characterization of Synthesized PEDOT in PVAc Matrix by FTIR-ATR, UV-Vis Spectrophotometric Analysis... 

The chemical polymerization of Py by CAN in PU solutions leads to the formation of PU/PPy composites. The composites were characterized by Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR], dynamic mechanical analysis (DMA], thermal gravimetric analysis (TGA], differential scanning calorimetry (DSC], X-ray photoelectron spectroscopy (XPS], and SEM measurements. The absorbances of the disordered H-bonded urethane carbonyl decrease with increasing Py concentration. The fraction of the hydrogen-bonded carbonyls is increased and the melting point increases with the increase of PPy content. These indicate the incorporation of PPy into PU may cause the complex due to the intermolecular interaction between the PPy and PU. SEM images of composite nanofibers show good distribution of the second component and the composite solution is proper to form conductive composite nanofibers. 

The IR spectra for a carbon black and a soot obtained by FTIR, ATR-IRS, and PDS have also been used for surface oxygen group analysis. The FTIR spectra obtained by O Reilly and Mosher (Figure 1.13) for a low surface area thermal black... 

Films deposited at this condition are characterized using various surface analysis techniques. FTIR-ATR, XRD, SEM, LSM, Raman spectral and XPS analyses give the conclusion that when methane is used as a precursor, deposited film is amorphous... 

Impurity inclusions and surface defects are a cause of many difficulties to the polymer producer and user. Equipment used for studying these phenomena discussed in Chapter 4 include electron microprobe x-ray emission/spectroscopy, NMR micro-imaging, various forms of surface infrared spectroscopy, e.g., diffusion reflection FTIR, ATR, also photoacoustic spectroscopy and x-ray diffraction - infrared microscopy of individual polymer fibres. Newer techniques such as scanning electron microscopy (SECM), transmission electron microscopy, time of flight secondary ion mass spectrometry (TOFSIMS), laser induced photoelectron ionisation with laser desorption, atomic force microscopy and microthermal analysis are discussed. 

FTIR-ATR spectra of thin PAA-g-PEG or PEM-PEG films on metal substrates can be used to gain information about the structure as well as the areal density of EG units or PEG chains on the surface, if the films contain primarily randomly oriented or aligned helical coils. The analysis can be made for ultrathin layers with thicknesses down to a few nanometers, because the metal substrate will not cmitribute signals interfering with vibrational bands of the organic coating. Near the metal surface the electric field of the... 

It is known [5] that an integrated absorbance (A) obtained from FTIR-ATR spectra is proportional to the amount of surfactant adsorbed at the solid liquid interface hence, it can be used for qualitative analysis of surfactant adsorption. As far as adsorption to hydrophobic surfaces occurs by attaching —CH3 and —CH2 groups of surfactant molecules then A is calculated as the area under the peak corresponding to C—H str. mode (see the paragraph above) of FTIR-ATR spectra. 

Two polymorphs are reported (Benson et al., 2000) Indications of polymorphic enantiotropy were found primarily through solubility analysis and FTIR-ATR (Nordstom and Rasmuson, 2006). 

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