Variation of Elasticity along Single Microfibrils of Bacterial Cellulose

Abstract

A NUMBER of models have been proposed for the internal fine structure of individual cellulose microfibrils which suggest variability both across and along the axis of the microfibril. Frey-Wyssling¹ has suggested that microfibrils are subdivided into four continuous crystalline strands, each about 70 Å. wide, which run parallel to the microfibril axis and are held together by a paracrystalline matrix. In contrast, Preston² has concluded that cellulose microfibrils from algæ are composed of a paracrystalline sheath surrounding a highly crystalline single core which is interrupted at random positions by less-crystalline material labile to electron bombardment. The positions occupied by this material may coincide with the sites of trace residues (Fremdgruppen) postulated by H. K. Meyer and van der Wyk and by Treiber³.