Hollow Al₂O₃ Microspheres Derived from Al/AlOOH·nH₂O Core‐Shell Particles

Abstract

Hollow Al2O3 spheres with ∼2 μm in diameter and ∼200 nm in wall thickness were prepared successfully via the calcination of the Al/AlOOH·nH2O core‐shell particles, prepared by wet‐chemical method using commercial microscale aluminum powders as raw materials, at 900°–1100°C in air. X‐ray powder diffraction, differential scanning calorimetric analysis, scanning electron microscopy, and transmission electron microscopy were used to characterize the obtained samples, and the possible formation mechanism was discussed. These hollow Al2O3 microspheres may have promising applications in insulators, lightweight fillers, and catalyst carriers because of their unique hollow structure.

Al2O3 hollow nanospheres prepared by fluidized bed chemical vapor deposition and further heat treatment

“…1,2 The large fraction of empty spaces endows them fascinating properties such as large surface area, low density, and high loading capacity, and demonstrates a large variety of applications, including micro-/ nanoreactors, catalysis, energy storage, biomedicine, sensors, environmental remediation, and so forth. 4 So far, various routes such as template method, 5-8 spray drying, 9,10 wet-chemical synthesis, 11 and flame spray pyrolysis have been developed to prepare Al 2 O 3 hollow micro-/nanospheres. 4 So far, various routes such as template method, 5-8 spray drying, 9,10 wet-chemical synthesis, 11 and flame spray pyrolysis have been developed to prepare Al 2 O 3 hollow micro-/nanospheres.…”

“…3 Among various hollow structures, Al 2 O 3 hollow micro-/nanospheres have great potentials as catalyst supports, drug carriers, and anti-reflection coatings due to their low cost, low thermal expansion, good thermal stability, high specific surface area, large void fraction, and unique refractive index properties. 4 So far, various routes such as template method, [5][6][7][8] spray drying, 9,10 wet-chemical synthesis, 11 and flame spray pyrolysis have been developed to prepare Al 2 O 3 hollow micro-/nanospheres. Among these methods, the flame spray pyrolysis method is an integrated synthesis process by combining liquid spray and vapor pyrolysis, which is simple, template-free, and can be easily manufactured in a large scale.…”

Effect of Heat on Hollow Multiphase Ceramic Microspheres Prepared by Self‐Reactive Quenching Technology

“…The hollow microsphere is a new material. It, due to special physical and chemical characteristics such as light, electricity, magnetism, and catalysis, which may be different from other kind of materials, exhibits important application value in the areas of biology, drug carrier, and functional material . The hollow ceramic microsphere, which is mentioned in the article, is prepared based on SHS, which contains advantages of ceramic material and hollow micro‐spheres.…”

Hollow Alumina Microsphere Chain Networks

“…Alumina is one of the most important ceramic materials due to its unique properties such as high stiffness and strength, excellent thermal and chemical stability, and peculiar to strength retention at high temperature 9 . Many efforts have been put to the synthesis of Al 2 O 3 with different morphologies such as wires, 10,11 rods, 12 belts, 13 tubes, 14–16 and spheres 17,18 . In this paper, we report the synthesis of an Al 2 O 3 chain network composed of hollow Al 2 O 3 microspheres.…”