Article,
Nano/subnano-tuning of porous ceramic membranes for molecular separation
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 46 (3): 349-361 (June 2008)14th International Sol-Gel Conference, Montpellier, FRANCE, SEP 02-07, 2007.
DOI: 10.1007/s10971-008-1712-5
Abstract
In sol-gel processing, porous ceramic membranes can be prepared by
sol-coating porous substrates and drying for gelling, followed by
a firing process. Ceramic membranes prepared by sol-gel processing
can be categorized into amorphous materials such as silica, and crystalline
materials such as alumina and titania. Amorphous silica networks,
which can be prepared by the polymeric sol route, have ultra-microporous
pores that allow small molecules such as helium and hydrogen to permeate.
On the other hand, crystalline materials, which are mostly prepared
by the colloidal sol route, have nano-sized pores in the range of
one to several nanometers. In this article, sol-gel derived SiO2
and TiO2 membranes with controlled pore sizes in the range of sub-nano
to nanometers will be reviewed with respect to membrane preparation
and to their application in the separation of the gas and liquid
phases. Ceramic membranes with high performance can be obtained by
precise control of membrane structures (pore size, pore size distribution,
thickness, pore shape, etc.) and membrane materials (SiO2, TiO2,
composite oxide, hybrid materials, etc.). Nano/subnano-tuning of
porous ceramic membranes is quite important for the improvement of
membrane permeability and selectivity.
