Moreover, FTIR spectra of untreated and pretreated CS were
also investigated (Fig. S3B in Supplementary materials). AE-CS,
FT-CS, AE-FT-CS and FT-AE-CS separated lignin from the fibers.
After the pretreatment, the reduction in the band intensity from
near 1724 cm1 representing carbonyl groups associated with lignin,
typically indicated possible cleavage of association of lignin
with polysaccharide and the removal of acetylated hemicellulose