
310 Engineering of Polymers and Chemical Complexity
2000 1500 1000 500
0.2
0.4
0.6
I
III
transmittance,%
d
1795
712
III
III
I
III
I
1431
876
cm
-1
FIGURE 1 The IR spectra of C. demersum samples:
I (control), II (lake Udomlya), and III (Cunette, Redkino township).
The IR spectral analysis shows that all samples under study have absorption bands
corresponding to the main chemical components of the plant: carbohydrates ~56% (of the
absolute dry weight), proteins ~18%, and fats~1% [1]. The existence of carbohydrates in the
plant is testified by absorption bands due to stretching vibration of CH
2
-groups at a frequency of
~2925 cm
–1
and OH-groups at ~3400 cm
–1
[5,21-22]. ...