Structure of β-chitin from Berryteuthis magister and its transformation during whisker preparation and polymerization filling

Models for the structures of the beta-chitin-protein complex of native and deproteinized squid pen (Berryteuthis magister) based on SAXS and WAXS data are proposed. Chitin fibrils of 25 angstrom in diameter and persistence length of 1200 angstrom are immersed in protein matrix. Average distance between fibrils is 42 angstrom. Deproteinization of the squid pen led to disappearance of the lateral fibril order stabilized by the protein matrix of the native sample. Swelling in water and acrylic acid resulted in an increase in the chitin 010 d-spacing to 14 and 18 angstrom, respectively. A preparation routine for individual chitin nanofibers of few microns in length and with diameter of 40-60 angstrom has been developed. During exfoliation of the chitin in acrylic acid the degree of acetylation does not change. Chitin-based nanocomposites can be prepared by polymerization of acrylic acid in swelled deproteinized samples which takes place mainly in the interfibrillar space of beta-chitin mainly. C) 2015 Elsevier Ltd. All rights reserved.