Fabrication of porous Al2O3–MgO–TiO2 ceramic monoliths by the combination of nanoemulsion templating and temperature-induced forming

• Published in: Journal of the European Ceramic Society 2021-02, Vol.41 (2), p.1514-1523
• Main Authors: Hessien, M.A., Khattab, R.M., Taha, M.A., Sadek, H.E.H.
• Format: Article
• Language: English
• Subjects: Aluminum titanate (Al2TiO5); Corundum; Nanoemulsion templating (NET); Rutile; Spinel (MgAl2O4); Temperature-induced forming (TIF)
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2020.09.056

•Oil droplets of nanoemulsion used to create pores through nanoemulsion templating.•Temperature-induced forming is used to shape composite as monoliths.•Composites have corundum, rutile, spinel and aluminum titanate phases.•Apparent porosity reaches 57 % with solid loading of 74 wt.%.•Electrical resistivity reaches 4.41E + 10 Ω.cm and are considered insulator. Porous ceramics have attracted considerable attention owing to the increased interest in their applications. Porous Al2O3–MgO–TiO2 ceramic monoliths were synthesized using nanoemulsion templating and temperature-induced forming method. The nanoemulsion (NE) is prepared by the phase inversion composition method. The ceramic slurry was dispersed by ammonium citrate trihydrate (ACT), and polyacrylic acid was used to induce gelling. The effect of different nanoemulsions and different metal oxide ratios on the fired monoliths were studied. The suspended ceramic, green bodies and fired monoliths were characterized by different characterization techniques. The combination of NE with ACT increases the zeta potential of ceramic slurries to ∼−28 mV. The combined routes successfully resulted in porous monoliths with an ironic microstructure with a homogenous distribution of pores. The apparent porosity increased to 57 % that in turn increased resistivity to 4.41E + 10 Ω.cm. The fired monoliths have corundum, rutile, spinel and aluminum titanate phases.