Inorganic Microporous Membranes for Gas Separation in Fossil Fuel ...

3 Experimental
3.3 Sol-gel derived TiO2, ZrO2 and binary oxide membranes
Sol-gel derived membranes are prepared using the supports with intermediate layers as
discussed previously. The final titania zirconia and binary metal oxide membrane
materials are prepared from polymeric sols, a process which will be outlined in the next
section. Finally, the formation of the sol-gel derived membrane is described and the
characterisations of these materials are discussed.
3.3.1 Polymeric TiO2, ZrO2 and binary oxide sol synthesis
The formation of a titania or zirconia polymeric sol can be controlled using a precursor
modifier to stabilise the alkoxide precursors. The ketone acetyl acetone and the amine
diethanolamine were selected as precursor modifiers. The sol syntheses in this work are
subdivided in to the ketone acetyl acetone and the amine diethanolamine route. A few
experiments were conducted with an alternative amine: diisopropanolamine.
3.3.1.1 Ketone route
The general procedure for synthesis of the acetyl acetone sols was carried out as follows
(Figure 18). A solution (1:1 molar) of acetyl acetone (Ac) and the corresponding
carboxylic acid was added under stirring to a solution of zirconium n-propoxide (Mateck,
70%) in 2-propanol (Aldrich), with a final molar ratio Ac/Zr ~1.
Figure 18 Procedure followed in the synthesis of different acetyl acetone 8YSZ sols
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