22 NIR Imaging
535
22.5.3 Monitoring of Biopolymer Photodegradation [31]
Photodegradability of biopolymer is a major concern for industrial applications, such
as packaging. In this study, the visualization of photodegradation is investigated
during photolysis process. The evolution of crystallinity at 1917 nm in the SNV
spectra of the film during photolysis is shown in Fig. 22.16. It can be noted that
the behavior of SNV spectra of PLA in the 1000–2000 nm was investigated prior
to imaging and the intensities of this band nm due to the second overtone of the
C = O stretching vibrations decreased with elapsed time. The crystallinity change in
the 0-min image arises from the temperature gradient of the designed hot stage. The
distribution of crystallinity is visualized: highly crystalline regions at the bottom of
the sample reached to homogeneity by the saturation of crystallinity. The amorphous
region at the top area of images depicted inhomogeneity of crystallinity by photolysis
process, clearly. Finally, this approach successfully demonstrated that the increase in
crystallinity due to photodegradation could be modeled using a logarithmic equation,
and the degradation speed is slightly promoted by the initial crystallinity of the sample
(Fig. 22.17).
22.6 Bioscience-Related Applications
NIR absorbance bands are mainly due to the functional groups containing a hydrogen
atom such as OH, CH and NH. The major components of biological organisms are
water, proteins, lipids, molecules which contain these functional groups. Therefore,
NIR spectroscopy and imaging can be a useful analytical tool for biological samples
to investigate structural changes of biomolecules. Furthermore, aqueous samples are
easier to handle for NIR spectroscopic analysis because water absorption in the NIR
wavelength region is much weaker than that in infrared (IR) region. Since NIR light
Fig. 22.16 NIR images for
the predicted crystallinity of
a PLA sample developed by
using SNV spectra subjected
to photolysis at 0 and 60 min.
Copyright (2015) Springer
535
22.5.3 Monitoring of Biopolymer Photodegradation [31]
Photodegradability of biopolymer is a major concern for industrial applications, such
as packaging. In this study, the visualization of photodegradation is investigated
during photolysis process. The evolution of crystallinity at 1917 nm in the SNV
spectra of the film during photolysis is shown in Fig. 22.16. It can be noted that
the behavior of SNV spectra of PLA in the 1000–2000 nm was investigated prior
to imaging and the intensities of this band nm due to the second overtone of the
C = O stretching vibrations decreased with elapsed time. The crystallinity change in
the 0-min image arises from the temperature gradient of the designed hot stage. The
distribution of crystallinity is visualized: highly crystalline regions at the bottom of
the sample reached to homogeneity by the saturation of crystallinity. The amorphous
region at the top area of images depicted inhomogeneity of crystallinity by photolysis
process, clearly. Finally, this approach successfully demonstrated that the increase in
crystallinity due to photodegradation could be modeled using a logarithmic equation,
and the degradation speed is slightly promoted by the initial crystallinity of the sample
(Fig. 22.17).
22.6 Bioscience-Related Applications
NIR absorbance bands are mainly due to the functional groups containing a hydrogen
atom such as OH, CH and NH. The major components of biological organisms are
water, proteins, lipids, molecules which contain these functional groups. Therefore,
NIR spectroscopy and imaging can be a useful analytical tool for biological samples
to investigate structural changes of biomolecules. Furthermore, aqueous samples are
easier to handle for NIR spectroscopic analysis because water absorption in the NIR
wavelength region is much weaker than that in infrared (IR) region. Since NIR light
Fig. 22.16 NIR images for
the predicted crystallinity of
a PLA sample developed by
using SNV spectra subjected
to photolysis at 0 and 60 min.
Copyright (2015) Springer