Metal oxide porous ceramic membranes with small pore sizes

• US 5,104,539 A
• Filed: 04/05/1991
• Issued: 04/14/1992
• Est. Priority Date: 08/06/1990
• 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:
  US07/681,088
• Time in Patent Office: 375 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, 252/315.9
• US Class Current: 210/500.25
• CPC Class Codes: B01D 2323/08 Specific temperatures applied
• 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 71/024 Oxides
• CPC Class Codes: B01J 2208/00592 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 2111/00801 Membranes; Diaphragms
• 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
• CPC Class Codes: C04B 38/0045 by a process involving the formation of a sol or a gel, e.g. sol-gel or precipitation processes
• CPC Class Codes: C04B 38/0051 characterised by the pore size, pore shape or kind of porosity

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 metal oxide ceramic membrane having a mean pore size of less than 40 Angstroms, the metal being selected from transition metals and mixtures thereof, and a surface area available for contact to a filtrate in excess of 15 square meters per gram.

2. A composition of matter as claimed in claim 1 wherein the mean pore size is greater than 15 Angstroms.

3. A composition of matter as claimed in claim 1 wherein the metal comprises titanium.

4. A composition of matter comprising a porous, transparent metal oxide ceramic membrane having a mean pore size of less than 40 Angstroms, the metal being selected from transition metals and mixtures thereof, and a surface area available for contact to a substrate catalysis in excess of 15 square meters per gram.

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

6. A composition of matter as claimed in claim 4 wherein the metal comprises titanium.