Synthesis and Formation Mechanism of Solid and Hollow Alumina Microspheres at the Water-Oil Interface
NH4Al (OH) 2CO3 (AACH) hollow spheres and solid spheres were successfully synthesized with water in oil in water (W/O/W) emulsion, applying the liquid-to-liquid-phase boundary of the micellar system as a template. During the facile procedure, no high pressure, high temperature, or other complex reaction conditions were required. Transmission electric microscope (TEM) images showed that all the hollow structural products have a good spherical morphology with an average diameter of 1 μm. The as-synthesized spheres had large diameters and thin shells of about 30 nm composed of numerous small nanocrystals. In addition, the AACH product can be calcined into Al2O3 without changing its shape.
L. M. Zhang et al., "Synthesis and Formation Mechanism of Solid and Hollow Alumina Microspheres at the Water-Oil Interface", Applied Mechanics and Materials, Vols. 110-116, pp. 997-1002, 2012