writer：Shuxuan Sun, Bin Liu, Xiaomeng Fu, Meijun Zhou, Guomin Bian, Yonglin Qi, and Xinlin Yang*,
keywords：Polymer/inorganic core-shell microsphere; Mn2O3/m-SiO2 double-shelled hollow microsphere; Braunite-1Q hollow microsphere; Mn2O3 hollow microsphere.
source：期刊
specific source：J Colloid Interface Sci, 438 (1), 269-276 (2015).
Issue time：2015年

Poly(methacrylic acid)-MnO(OH)₂/SiO₂ core-shell microspheres were prepared by the sol-gel hydrolysis of tetraethylorthosilicate (TEOS) in presence of poly(methacrylic acid)-Mn(II) (PMAA-Mn²⁺) as template with ammonium hydroxide anion as the catalyst and n-octadecyltrimethoxysilane (C₁₈TMS) as pore-directing reagent. The PMAA-Mn²⁺ core was prepared by incubation of Mn²⁺ cations with PMAA microspheres via the coordination between the carboxylate anion group on PMAA microsphere and Mn²⁺ cations. During this process, the Mn(II) specie were formed as white Mn(OH)₂ at first and it was subsequently oxidized into brown MnO(OH)₂ in air. The Mn₂O₃/mesoporous silica (Mn₂O₃/m-SiO₂) double-shelled hollow microspheres (DSHMs) were prepared through the calcination of the PMAA-MnO(OH)₂/SiO₂ core-shell microspheres at 600 ^oC for selective removal of the PMAA template and the pore-directing organic component from C₁₈TMS, in which the crystalline structure of DSHM was developed into Braunite-1Q via the reaction between Mn₂O₃ inner-shell and silica outer-shell by annealing the DSHMs under higher temperatures of 800 and 900 ^oC. The Mn₂O₃ hollow microspheres (HMs) were prepared through the selective removal of the silica layer from the DSHMs by sodium hydroxide aqueous solution, which exhibited structure integrity and good ethanol dispersity due to presence of mesoporous structure.