Figure 5.
(a) X-ray diffraction profiles of squid pen samples treated with 0 (water), 4, 5, 6, 7, and 8 M HCl. Lines in red correspond to the diffractions characteristic of α-chitin; (b) enlarged profiles of Figure 5a. α, βa, βm, and βd represent the peak positions of α-chitin, anhydrous β-chitin, β-chitin monohydrate, and β-chitin dihydrate from the literature data.15,52,53 Colored dots represent the peak top position of the profiles; (c) X-ray diffraction profiles of the EDA complex of squid pen treated with 0 (water), 4, 5, 6, 7, and 8 M HCl. Shades denoted as α, *, and β are the same as in Figure 4. Colored dots represent the peak top position of the profiles.