Production of NiMn2O4 Hollow Spheres and CoFe2O4 Bowl-like Structures by Using Block Copolymer Stabilized Polystyrene Spheres as a Hard Template

Abstract

The aim of this study is to highlight the use of polystyrene (PS) latexes stabilized with block copolymers as a hard template in the production of metal oxide hollow spheres. PS latexes produced by dispersion polymerization by stabilizing with tertiary amine methacrylate-based diblock copolymer were used as a hard template in the preparation of nickel manganese oxide (NiMn 2 O 4 ) hollow spheres and iron cobalt oxide (CoFe 2 O 4 ) bowl-like structures. Thanks to the diblock copolymer stabilizer with tertiary amine functional groups on the PS surface, precursor salts of CoFe 2 O 4 and NiMn 2 O 4 were rst homogeneously deposited on the surface of PS latexes with a controlled precipitation technique. Then, metal oxide hollow spheres and bowl-like structures were produced by calcination. XRD results showed that CoFe 2 O 4 and NiMn 2 O 4 structures were successfully obtained after calcination. The thermogravimetric analysis results showed that the CoFe 2 O 4 and NiMn 2 O 4 contents of the hybrid PS spheres were in the range of 26.0-28.6 wt%. SEM images showed that the inorganic-polymer spheres fused with each other after calcination to form larger magnetic CoFe 2 O 4 bowl-like structures. SEM images also indicated successful production of highly rough NiMn 2 O 4 hollow spheres with nano-sheets on the surface.