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

3 Experimental
Figure 19 Procedure followed in the synthesis of different amine sols
3.3.2 Drying and sintering of TiO2, ZrO2 and binary oxide bulk material
The polymeric sols were dried in a glass beaker at 80ºC for 4 hours to remove the
propanol and the dried further at 140ºC to the obtain bulk material. The dried powders
were characterised with DTA/TG and element analyses (carbon and nitrogen). The
powders were calcined at 400, 500, 550 and 600ºC for 2 hours with heating rates of
0.4ºC/min. The YSZ bulk materials were further calcined at 800 and 1080ºC for 2 hours.
Organic extractions were performed by mixing 1 wt% suspensions of the gelled sols in a
n-propanol/n-heptane (mol ratio of 2:1) solution. These mixtures were refluxed overnight
followed by conventional washing with H2O and drying.
3.3.3 Microporous TiO2, ZrO2 and binary oxide membrane preparation
The polymeric sols were applied on suitable substrates by spin coating with a rotating
speed ranging from 500 to 5000 RPM or by dip coating. The wet films were dried at
room temperature or in a climate chamber set at 40ºC with 60% humidity for 3 hours.
The films were fired at 400, 450, 500 or 600ºC for 2 hours with heating rates of
0.4ºC/min. These steps were repeated to form a second layer. The films were made on a
microscope glass slip (Chance Propper Ltd.) or on γ-Al2O3 membrane supports described
in the first section of this chapter.
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