SIZE AND ARRANGEMENT OF ELEMENTARY FIBRILS IN CRYSTALLINE CELLULOSE STUDIED WITH SCANNING-TUNNELING-MICROSCOPY

Scanning tunneling microscopy (STM) was used to investigate the ultras tructure of cellulose. The materials used in the experiments were cott on fiber, dewaxed cotton fiber, and microcrystalline cellulose. The re sults showed that the elementary fibrils in all these kinds of cellulo se could be directly observed from the surface and cross-sectional vie w with high resolution. The elementary fibrils assembled together in p arallel, and their lateral dimension showed a great variability in dif ferent kinds of cellulose, but was uniform in the same kind of cellulo se. Elementary fibrils were the smallest structural units of cellulose , and they further aggregated into microfibrils, and the microfibrils constituted fibrils. In each gradation, the fibers piled up in paralle l. STM was useful in studying the fine structure of cellulose. (C) 199 7 American Vacuum Society.