PREPARATION AND CHARACTERIZATION OF NIOBIUM OXIDE-COATED CELLULOSE FIBER

The Nb2O5/cellulose composite was prepared by reacting alpha-cellulose with NbCl5 . n(OC2H5)(n), in nonaqueous solvent, under nitrogen atmos phere and submitting the obtained material to hydrolysis, An increase in the crystallinity degree is observed in the composite material beca use the precursor reagent reacts with the amorphous phase of the cellu lose fibers. Loadings between 4.5 and 16.0% of the oxide were achieved and in every case the oxide particles uniformly cover the fiber surfa ce, Lewis and Bronsted acid sites were determined by using pyridine as the basic molecular probe. (C) 1996 Academic Press, Inc.