ZnSe ATR accessory

To demonstrate that the gradient effect can be removed in an aligned system, similar experiments were performed by measuring a homogeneous sample of mineral oil (refractive index c 1.48), using both the ZnSe ATR accessory and the diamond ATR accessory (Supercritical Fluid Analyzer, Specac, UK). Both results... 

Figure 10.5 ATR-FT-IR image of mineral oil measured with a ZnSe ATR accessory showing the integrated absorbance at 1480-1420cm. The histogram showing the number of detector pixels for different values of the integrated absorbance at the same range for the ATR-FT-IR measurement.

Using an inverted-prism diamond ATR accessory, it has been demonstrated that the FOV was about 500 pm X 700 pm ( 5x magnification). For the inverted-prism ZnSe ATR accessory, which does not contain any lenses (e.g.. Oil Analyzer, Specac,... 

CXE2C1, C1E3C1, and CXE4C1 were commercially supplied, while CxEsCx and CxEgCx were prepared by the Williamson ether synthesis. The infrared spectra of aqueous solutions of these compounds were measured for various concentrations at room temperature by using a horizontal ATR accessory with a ZnSe prism. Tibe lowest concentration studied was a mole fraction of approximately 0.005. The spectra were recorded on a JASCO FT/IR-7300 spectrometer. Each of the spectra was obtained by the coaddition of 200 scans at a resolution of 4... 

Large ZnSe Variable angle ATR accessory Medium ZnSe Diamond ATR Micro ATR with lOx Ce objective... 

IR analysis was carried out to evaluate structural changes of CMC and CFF and its grafted copolymers, by means main functional groups signals. IR spectra were recorded with a Perkin-Elmer Spectrum One Fourier Transform IR spectrophotometer, using an Attenuated Total Reflactance (ATR) accessory, with ZnSe plate, using 12 scans and resolution of 4 cm", ranging from 4000 to 600 cm-i. 

ATR objective ATR is used for surface analysis using physical contact with a sample surface. The objective utilizes a crystal of material for the actual physical contact with the sample. Typical crystal materials include diamond (Di), germanium (Ge), silicon (Si), and zinc selenide (ZnSe). ATR measurements can yield excellent quality spectra provided that the contact pressures of the ATR crystal and the sample are held constant reproducible data require reproducible contact pressure. Commercial contact gauges are available from suppliers of microscope accessories. One-percent reproducibility is typically achieved when keeping the contact pressure constant. ATR crystals are generally ZnSe with a refractive index of 2.42 and an angle of incidence of 45°. Sample pen-... 

Something to be careful about when stndying liquids is that some crystals, such as ZnSe, will react with or dissolve in strong acids or bases. The usable pH ranges for a number of ATR crystals are listed in Table 4.12. Another issue with ATR is that volatile liquids, such as acetone, may evaporate before their spectrum is measured. Many ATR accessories are equipped with volatiles covers that are placed over the liquid in an attempt to prevent evaporation. The author has had mixed results with these, and in his experience, highly volatile liquids may be best sampled using the sealed liquid cell method discussed earlier. 

Figu re 9.5 Available accessories for the imaging macrochamber, (a) Transmission (Broker Optik GmbH, Ettlingen, Germany) (b) Reflection (Pike Technologies, Madison, USA) (c) ATR with a ZnSe crystal (Harrick Scientific Products inc.. New York, USA). 

Figure 9.3 Schematic representations of prism diamond imaging accessory, and (d) optical setups for ATR FT-IR spectroscopy as a ZnSe expanded field of view setup. (Repro-typically used in imaging (a) micro-ATR using duced from [3] with the permission of the a Ge crystal and microscope, (b) an inverted Society for Applied Spectroscopy [3].)...

The ATR apparatus with a diamond IRE, which is not supported on ZnSe, is less robust in its mechanical strength, but it has the advantage of offering an extended spectral range from 4000 cm" down to about 400 cm" when used in combination with a triglycine sulfate (TGS) detector. A similar accessory using Ge as the IRE is also commercially available. ATR apparatus designed specifically for use with FT-IR spectrometer microscope systems have also been developed and are commercially available. 

A Broker AMX-300 NMR instrument was used to collect H spectra at 300 Mhz. The polymer was also characterized by attenuated total reflectance (ATR) FTIR sepectroscopy using a Thermo Electron 6700 instrument and a Pike VeeMax II accessory with 60° ZnSe crystal. The FTIR system was purged with dry air and a clamping force of approximately 5... 

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