Flame Aerosol Synthesis of Core-Shell and Janus Magnetic Particles
H. Yim, A. Khasanov, B. Guo
Texas A & M University, US
Keywords: flame spray pyrolysis, Janus, Core-Shell, iron, silicon
Abstract:Flame Aerosol method has been widely used in the synthesis and processing of nano-materials. The versatility of these processes gives researchers great flexibility in tailoring the chemical composition, crystal structure, morphology and size of the product materials. In this study, we used a modified flame spray pyrolysis method to synthesize FexOy/silica composite particles. By varying the flame synthesis conditions, either core-shell or Janus particles were generated. The core-shell structure particles had a mean diameter of approximately 1 Ám, and consisted of an iron oxide/silicate core and a uniform silica shell. These particles were chemically stable in 0.75 M sulfuric acid. The Janus particles were in range of 10-100 nm, composed of a gamma-Fe2O3 hemisphere and a silica hemisphere. Both types of particles showed superparamagnetism. They can be suspended in liquids and easily separated from the suspension with a magnet. The core-shell particles may be used in biological separation or as retrievable catalyst support for corrosive fluids. The Janus particles, with iron oxide giving the magnetic property, and the other side providing a base for functionalization, may be used for targeted drug delivery and biological labeling.