文档介绍：Reverse Osmosis of Nonaqueous Solutions
through Porous Silica-Zirconia Membranes
Toshinori Tsuru, Masashi Miyawaki, Tomohisa Yoshioka, and Masashi Asaeda
Dept. of Chemical Engineering, Hiroshima University, Higashi-Hiroshima, 739-8527, Japan
DOI
Published online September 28, 2005 in Wiley InterScience (.com).
Porous silica-zirconia membranes with pore diameters from to 2 nm were prepared
by a sol-gel process, and applied to the separation of alcohols (hexanol, octanol, decanol)
and alkanes (hexane, decane, tetradecane) in ethanol solutions by reverse osmosis over
the temperature range from 25 to 60° C. A silica-zirconia membrane with a pore diameter
of 1 nm showed a molecular weight-cut-off (MWCO) of 200 in ethanol solutions. Rejection
increased with the applied pressure, for both alcohol and alkane solutes. However, the
rejection of alcohols was found to decrease with temperature, while that for alkanes
remained nearly constant. The separation characteristics were examined for the following
membrane parameters: solvent permeability, Lp, reflection coefficient, , and solute
permeability, P, based on the Spiegler-Kedem equation. The viscosity of solutions and the
diffusivity of alkanes and alcohol solutes in nano-sized pores were found to show a larger
temperature dependency than in bulk. The diffusivity of alkane solute