Patent ID: 6943123
Filing Date: 2005-09-13
Classification: B01D

Abstract:
1. A method of producing weakly branched silica membranes coated onto a substrate using a two-step catalysed hydrolysis sol-gel process including the steps of: forming a tetraethylorthosilicate (TEOS)/ethanol solution; placing the TEOS/ethanol solution in an ice bath; forming an acid/water solution; adding the acid/water solution to the TEOS/ethanol solution to form a TEOS/ethanol/acid/water solution; refluxing the TEOS/ethanol/acid/water solution; preparing a two-step sol by adding water and nitric acid to the refluxed TEOS/ethanol/acid/water solution and initiating a two-step sol-gel process; depositing a membrane film layer on a substrate from the two-step sol to form a substrate coated with weakly branched silica membranes.