Enzymatically produced nano-ordered short elements containing cellulose I_β crystalline domains

This paper reports an attempt to characterize the residues extracted after enzymatic hydrolysis of Cladophora microcrystalline cellulose comprising two crystalline allomorphs of cellulose, Iα and I_β. Cellulose I_α is preferentially hydrolyzed by Trichoderma cellulase (Hayashi, Ishihara, Sugiyama, & Okano, 1998a). This selective hydrolysis process produced short elements. X-ray diffraction, electron diffraction and FT-IR analyses revealed that these short elements were highly crystalline, similar to the untreated microcrystalline cellulose, and mostly consisted of the I_β phase. The length distribution of the crystalline elements was ca. 350 nm. Furthermore, the average length of 350 nm corresponded to the degree of polymerization of 690 for β-glucan chains obtained by size exclusion chromatographic analysis. The close agreement indicates that individual molecular chains may be extended in the longitudinal direction of the obtained crystalline element. These characteristic short elements have the potential to act as nano-ordered particles and may be useful as fillers to enhance the mechanical properties of various materials.