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

4 Results and discussion
Solid Content,
8YSZ wt%
0
2.5
5.0
10
15
Max §
73
Carboxylic Acid
Acetic Propanoic Caproic Nanonic
12 6.6 3.2 2
Viscosity (mPa·s)
Figure 42 Viscosity of the obtained sols as a function of the type of carboxylic acid and the solid
concentration.
4.3.1.2 Amine approach
The synthesis of sols from diethanolamine (DEA) modified precursors results in 0, 25,
50, 66, 75, 90, 100 mol% TiO2 in ZrO2 sols that are stable at least for several weeks. The
particle sizes of these DEA sols as measured by means of dynamic light scattering (DLS)
and small angle X-ray scattering (SAXS). These results indicate that all sol particles are
similar in size (2-5 nm) and that their size does not depend significantly on the Ti to Zr
ratio (Table 21-Figure 43).
Replacing the precursor modifier DEA with diisopropanolamine (DIPA) resulted in
similar average particle sizes (Figure 44).
Table 21 Particle sizes with errors between brackets and fractal dimensions of mol % TiO2 in ZrO2 DEAsols
Sample Concentration Particle size by SAXS in nm Fractal dimension
TiO2 2 wt% 3.8 (±0.5) 1.37 (±0.01)
Ti0.5Zr0.5O2 2 wt% 2.8 (±1.0) 1.04 (±0.01)
Ti0.5Zr0.5O2 4 wt% 3.6 (±1.0) 1.16 (±0.01)
ZrO2 2 wt% 2.0 (±0.5) -