Structure and properties of composite films prepared from cellulose and nanocrystalline titanium dioxide particles

Composite films were successfully prepared from cellulose and two kinds of nanocrystalline TiO2 particles in a NaOH/urea aqueous solution (7.5:11 in wt%) by coagulation with H2SO4 solution. The structure, morphology, and properties of the films were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, TGA, tensile testing, UV-vis spectroscopy, and antibacterial test. The results indicated that TiO2 particles in a cellulose matrix maintained the original nanocrystalline structure and properties. TiO2(I) (anatase) and TiO2(II) (the mixture of anatase and rutile) particles exhibited a certain miscibility with cellulose. The tensile strength of two kinds of composite films was higher than 70 and 75 MPa, when the content of TiO2(I) and TiO2(II) was 4 and 11 wt %, respectively. The cellulose composite films containing nanocrystalline TiO2 particles displayed distinct antibacterial abilities and excellent UV absorption. This work provides a potential way for preparing functional composite materials from cellulose and inorganic nanoparticles in a NaOH/urea aqueous solution, without a destruction of the structure and properties of the particles. (c) 2006 Wiley Periodicals, Inc.