The IR spectrum of the CS–CA nanogel was recorded on an FT/IR-
430 Fourier transform infrared spectrometer at 20 ◦C following the
method described by (Shigemasa et al., 1996). For the IR spectroscopic
analysis, 2mg of CA, 2mg of CS and 300Lof CS–CA nanogel
were separately mixed with 100mg of KBr and made into pellets.