$TiO_2$ gels were prepared by sol-gel method from alkoxide as a stating material. The $TiO_2$ fibers were obtained from "polymeric sols," while $TiO_2$ membranes were produced from "colloidal sols".
It was seen from $N_2$ adsorption analysis that $TiO_2$ gels had narrow pore size distribution. Particle sizes of sols measured by in situ light scattering were 87-164 nm in stable colloidal sols. Supported $TiO_2$ membranes with thickness of 1.5-3㎛ have been fabricated. This supported membranes had ultra fine pores (4-6nm) with narrow pore size distributions. It was also been found that Knudsen diffusion was predominant in the permeability of supported membranes.
During aging, polymeric sols underwent transitions in steady shear flow behavior from Newtonian to shear thinning to thixotropic. Titanic fibers were produced at the high viscous state exhibiting shear thinning flow behavior. In this study, stable fibers were obtained from the spinnable sols up to 150㎛ in diameter.
