Tese_Tânia Vieira.pdf - Ubi Thesis

Chapter III – Results and Discussion
of chitosan (Anitha et al. 2009; Delair 2011; Potara et al. 2011). One peak at 1585.68 cm -1 was
observed and corresponds to the deformation in the chitosan (Delair 2011).
In dextran spectrum was verified a peak at 2950.07 cm -1 that corresponds to a C–H
stretching (Kumar et al. 2012). The peak at 1636.30 cm -1 was also observed and corresponds to
the sulfate asymmetric stretching (Delair 2011). Another peak was found at 1220.72 cm -1 that
belongs to S=O vibrations (Delair 2011).
When examining FT-IR spectrum of chitosan/dextran nanoparticles, changes in the amine
and sulfate absorption bands were detected (figure 10 red). These spectral changes were
attributed to the electrostatic interaction between the chitosan amine and dextran sulfate
groups (Anitha et al. 2011). The formation of the chitosan/dextran nanoparticles was noticed by
the appearance of a specific band at 1531.68 cm -1 that was also observed by Delair and
coworkers (Delair 2011). The band at 1220.72 cm -1 in the dextran spectrum, broadened and was
separated into two peaks along with the complexation process, as already observed by Delair and
coworkers (Delair 2011). Tyaboonchai and collegues reported that the complex formation by a
shift of the N-H bending adsorption at 1652 cm -1 and 1599 cm -1 for chitosan, to 1623 cm -1 in the
chitosan/dextran nanoparticles was consistent with the presence of electrostatic interaction
(Tiyaboonchai et al. 2007; Delair 2011). Such phenomenon was also herein observed, the
appearance of a band at 1633.41 cm -1 in the chitosan/dextran nanoparticles spectrum.
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