Characteristics of Alumina-Supported TiO2 Composite Ultrafiltration Membranes Prepared by the Sol-Gel Method

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J. Korean Ceram. Soc. > Volume 29(2); 1992 > Article

Journal of the Korean Ceramic Society 1992;29(2): 107.

Sol-Gel 법으로 제조한 알루미나 담체의 $TiO_2$ 복합 한외여과막의 특성

현상훈, 최영민

연세대학교 세라믹공학과

Characteristics of Alumina-Supported TiO2 Composite Ultrafiltration Membranes Prepared by the Sol-Gel Method

ABSTRACT

Alumina supports for TiO2 ultrafiltration membrane coating were prepared by presintering disk-type preforms at 140$0^{circ}C$. These supports showed uniform microstructures which had the apparent porosity of 40%, the pore size distribution in the range of 0.1~0.5${mu}{textrm}{m}$, and the water flux of 1400ι/$m^2$.h at the pressure difference of 10 atm. The optimum pH and concentration of the TiO2 sol for coating were 0.8 and 1.0 wt%, respectively, and sol particles were identified as rutile forms of 20 nm size. Crack-free alumina-supported rutile TiO2 membranes could be prepared through well controlled drying and heating the gel layer coated by the sol-gel dipping. The pore size of the TiO2 membranes heat-treated at 50$0^{circ}C$ for 2 hrs was 30~80$AA$, and their thickness varied from 1.1 to 3.8 ${mu}{textrm}{m}$ in accordence with the dipping time (4~40 min). The flux of water through this composite membrane at 10 atm was found to be in the range from 800 to 1100ι/$m^2$.hr depending on the dipping time (10~40 min). The membrane thickness increased linearly with the square root of the dipping time and the slope was 0.62 ${mu}{textrm}{m}$/{{{{ SQRT { min} }}.