Alkali-induced conversion of beta-chitin to alpha-chitin.
Crystal conversion of beta-chitin to alpha-chitin by aq. NaOH treatment was studied for a highly crystalline beta-chitin sample from diatom spine. The minimum NaOH concentration to cause swelling was between 25% and 30% w/w. The alkali-swollen material was poorly crystalline and was regenerated as alpha-chitin on washing with water. This conversion caused total collapse of the original microfibrillar morphology. These features are similar to those of 7 N-8 N HCl treatment reported earlier, but alkali treatment was free from depolymerization or deacetylation.
Noishiki
Yasutomo
Y
Department of Biomaterials Science and Laboratory of Marine Biochemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan. noishiki@sbp.fp.a.u-tokyo.ac.jp
Takami
Hiroko
H
Nishiyama
Yoshiharu
Y
Wada
Masahisa
M
Okada
Shigeru
S
Kuga
Shigenori
S
D000468:Alkalies / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002686:Chitin / Q000737:chemistry* / Q000648:ultrastructure; D018360:Crystallography, X-Ray; D008854:Microscopy, Electron; D012972:Sodium Hydroxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D000468:Alkalies; D002686:Chitin; D012972:Sodium Hydroxide