Surface Fractal Dimension of Perovskite-Doped Alumina Membrane: Influence of Calcining Temperature

The surface fractal dimension, D , and pore size distribution of perovskite-doped alumina membrane prepared via the sol–gel method were determined from their nitrogen adsorption isotherms. The D value was calculated using the Frenkel–Halsey–Hill method. The D value increased with increasing temperature due to membrane shrinkage. The pore size distribution pattern of perovskite-doped alumina membrane showed a narrow pore size when the temperature was increased from 400° to 800°C. The isotherm type was characterized as Type IV. Smoothing and sintering effects contributed to the decreasing trend of surface fractal dimension at a high temperature. The surface fractal dimension increased when the perovskite ratio in alumina membrane was increased.