title: Fabrication of porous nanocomposites with controllable specific surface area and strength via suspension infiltration.
abstract: Porous ceramics are promising candidates for a variety of applications, including separation membranes, catalyst supports, tissue engineering scaffolds, energy storage devices, and microelectronics. We describe a novel method for creating porous ceramics with controllable specific surface area and high strength. The fabrication procedure involves infiltrating aqueous suspensions of silica nanoparticles into a porous ceramic scaffold. The samples are then freeze-dried to maintain a homogeneous distribution of nanoparticles, followed by partial sintering to bond the infiltrated nanoparticles into place. By repeating this infiltration process multiple times, the specific surface area of the composite can be varied from less than one to well over 100 m(2)/g. It is also found that this infiltration increases the mechanical strength of the composite. Water flux experiments demonstrate the potential use of these materials as liquid membranes, with no detectable damage to the structure observed after these flux tests. While this initial work focused on silica nanoparticles and ceramic scaffolds, the basic approach would to applicable to a wide variety of other materials, meaning that the method described here would be generally applicable for creating porous materials with precisely controllable properties.
authors.affiliation: Materials Science and Engineering Department, 127 Randolph Hall, Virginia Tech, Blacksburg, Virginia 24060, USA.
authors.forename: Wenle
authors.initials: W
authors.lastname: Li
authors.forename: Kathy
authors.initials: K
authors.lastname: Lu
authors.forename: John Y
authors.initials: JY
authors.lastname: Walz