Near infrared complex polymers

Near-infrared absorption spectroscopy is increasingly used in agriculture, food science, medicine, fife sciences, pharmaceuticals, textiles, general chemicals, polymers, process monitoring, food quality control and in clinical in vivo measurements [215, 216]. The increase in popularity is largely due to the availability of miniaturised NIR-spectrometers by a variety of vendors (e.g. Ocean Optics Inc.). The most promising applications of NIR-absorbance spectroscopy clearly lie in process control, because of the relatively low complexity of the sample in chemical and biochemical processes, e.g. compared to biological tissues. Also in food quality control... 

The examples discussed above can explain the complexity of the water band. The complexity originates from the ability of water molecules to form hydrogen bonds in various manners. The understanding and analysis of near-infrared spectra can provide information on the nature of the water environment. The wavenumbers of the stretching-bending combination of the water adsorbed in some polymers and composites are summarized in Table 2.7. 

The copolymers described above form intramolecular charge-transfer complexes which are deeply coloured and extend the spectral response of these materials into the visible and near infrared region [172]. Furthermore problems with the toxicity of acceptor molecules like TNF may be overcome by covalent fixation of acceptor groups to a polymer backbone. 

The UV-vis-near-IR absorption spectrum of the solution of the protonated polymer exhibits MLCT bands and valence tautomerization similar to those of 1,8-Fc2Aq as shown in Fig. 3.32, indicating the formation of fulvene complexes in the main chain in solution. Infrared spectrum of the protonated polymer also shows the similarity with that of l,8-Fc2Aq, namely, half the CC triple bond remains. 

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