Control of the Crystal Structure of microbial Cellulose During nascent Stage

摘要

The structure of the product, from an Acetobacter culture in the presence of Fluorescent Brightener. Direct Red 28, and Direct Blue 1, 14, 15 and 53, characterized by an X-ray diffractormeter is a crystalline complex. On the other hand, solid-state ~(13)C-NMR spectroscopy reveals that the product is noncrystalline. However, the X-ray result of the product sample suggests that the dye moleucle is included in the form of a monolayer between the cellulose sheets in the complex corresponding to the (110) plane of microbial celuose. But the celluloses regenerated from the Fluorescent Brightener product, the Direct Red 28 product, and the rest of te dye products are celluloses I, IV, and II, respectively. More specifically, the ~(13)C-NMR spectra revealed that the crystal types of cellulose from the Fluorescent Brightener and Iret Red 28 products are I_#beta# and IV_I, respectively. Thus, the crystal structure of te produt and the regenerated cellulose depends mainly on the position and number of the sulfonate groups in a direct dye and the nteractions of the dye with the noncrystalline microbial cellulose inthe nascent stage. The conformation and arrangement of the nascent celulose chain changes when a direct dye adheres to it.