Metal oxide porous ceramic membranes with small pore sizes

• US 5,006,248 A
• Filed: 08/06/1990
• Issued: 04/09/1991
• Est. Priority Date: 10/23/1989
• Status: Expired due to Term

• Current Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Original Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Inventors: Anderson, Marc A., Xu, Qunyin
• Primary Examiner(s): Sever, Frank
• Application Number:
  US07/563,013
• Time in Patent Office: 246 Days
• Field of Search: 210/500.26, 210/500.25, 210/510.1, 264/48, 264/63, 264/45.5, 106/436, 106/437, 106/122, 501/12, 252/315.01
• US Class Current: 210/500.25
• CPC Class Codes: B01D 2325/02 Details relating to pores or porosity of the membranes
• CPC Class Codes: B01D 2325/0283 Pore size
• CPC Class Codes: B01D 67/0048 by sol-gel transition
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: B01D 71/024 Oxides
• CPC Class Codes: B01J 19/2475 Membrane reactors
• CPC Class Codes: B01J 2208/00017 Controlling the temperature
• CPC Class Codes: B01J 2208/00548 Flow
• CPC Class Codes: B01J 2208/00592 Controlling the pH
• CPC Class Codes: B01J 2219/00051 Controlling the temperature
• CPC Class Codes: B01J 2219/00164 controlling the flow
• CPC Class Codes: B01J 2219/00177 controlling the pH
• CPC Class Codes: B01J 35/59 Membranes
• CPC Class Codes: B01J 8/009 Membranes, e.g. feeding or removing reactants or products to or from the catalyst bed through a membrane
• CPC Class Codes: C04B 35/46 based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C04B 35/486 Fine ceramics
• CPC Class Codes: C04B 35/49 containing also titanium oxides or titanates
• CPC Class Codes: C04B 35/624 Sol-gel processing

Abstract

A method is disclosed for the production of metal oxide ceramic membranes of very small pore size. The process is particularly useful in the creation of titanium and other transition metal oxide membranes. The method utilizes a sol-gel process in which the rate of particle formation is controlled by substituting a relatively large alcohol in the metal alkoxide and by limiting the available water. Stable, transparent metal oxide ceramic membranes are created having a narrow distribution of pore size, with the pore diameter being manipulable in the range of 5 to 40 Angstroms.

Claims

1. A composition of matter comprising a porous, transparent titanium dioxide ceramic membrane having a mean pore diameter of less than 40 Angstroms and a surface area available for contact of a filtrate in excess of 200 sq. m/g.

2. A composition of matter as claimed in claim 1 wherein the mean pore diameter is greater than 5 Angstroms.

3. A composition of matter comprising a porous, transparent metal oxide ceramic membrane having a mean pore diameter of less than 40 Angstroms, a metal selected from the group consisting of transition metals and mixtures thereof and a surface area available for contact of a filtrate in excess of 200 sq. m/g.

4. A composition of matter as claimed in claim 3 wherein the mean pore diameter is greater than 15 Angstroms.