Figure 3.
FTIR characterization of chemical composition along the gelatin/chitosan cross-gradients. A: FTIR spectra of gelatin/chitosan composite sections at different positions. B: Quantification of gelatin content at different locations along the composite material. Black diamonds indicate experimental values obtained from linear calibration curve (inset); red diamonds indicate values extrapolated from a parabolic fit (red dashed line) to the black diamonds. Inset: Linear calibration derived from the ratios of Amide I and II peak heights (at 1,645 cm−1 and 1,547 cm−1, respectively) in six blends of known gelatin/chitosan composition.