Pore Surface Fractal Dimension of Sol-gel Derived Nano-porous Silicazirconia Unsupported Membrane

Pore surface roughness changes in SiO2-ZrO2 unsupported membranes induced by chemical composition and heating process have been investigated by the analysis of surface fractal dimension. Fractal features were analyzed from N2 adsorption– desorption measurements. It was found that a decrease in the surface fractal dimension occurs while the zirconia content increases in the unsupported membranes heated at 500 ºC. The surface fractal dimension of membrane with 30 mol% silica content slightly increased in the heating range of 200 to 500 ºC due to the shrinkage and increase of mass fractal dimension of silica clusters.