Fig. 6. FT-IR curves of starch powder (a), chitosan powder (b) and starch/chitosan
membranes with starch-to-chitosan ratios of 7:4 (c), 5:4 (d) and 3:4 (e).
Transmittance
Water absorption
Water sensitivity is another important property for practical
applications of starch/chitosan membranes. To analyze the hydrophobic/hydrophilic
characters of the obtained membranes, the
properties of water absorption were tested and the results were given
in Fig. 3. The value of WAQ of membranes showed minor variation
irrespective of the component ratios. With the prolonging of
swelling time, WAQ enlarged to get the equilibrium. By comparing
WAQ values of membranes with different starch contents, it comes
to the conclusion that the contents of starch did not obviously affect
the water absorption, although the presence of starch enhanced
the hydrophobicity of blend membranes as a result of the
hydrophobic chains of starch.
Wavenumbers /cm-1