Industrial & Engineering Chemistry Research, Vol.59, No.20, 9532-9540, 2020
Facile Construction of Porous Magnetic Nanoparticles from Ferrocene-Functionalized Polyhedral Oligomeric Silsesquioxane-Containing Microparticles for Dye Adsorption
Previously, much attention has been paid to prepare porous magnetic silica micro/nanoparticles, but most of the reported methods are limited by sophisticated procedures and strict synthetic conditions. Herein, we established a facile approach to prepare porous Fe3O4@SiO2 composite nanoparticles through thermal calcination of ferrocene-functionalized polyhedral oligomeric silsesquioxane-containing microparticles (Fc-PCMs). The key point of this approach is utilizing a nanosized, cagelike POSS molecule as the porogen and ferrocene as the magnetic source to simplify the preparation procedures. Taking advantages of the thiol-Michael dispersion polymerization technique, Fc-PCM precursors with tunable ferrocene were rapidly synthesized under ambient conditions, and the subsequent thermal calcination process imparted magnetic properties and a porous nanostructure to them simultaneously. The precursors and ultimate particles were characterized by various techniques. It was found that the saturation magnetization and surface area of these particles were affected by the calcination temperature, and the optimal condition was 600 degrees C. The ultimate particles exhibited a large surface area (i.e., 655.3 m(2) g(-1)), nanopores (pore size was around 1.9 nm), good magnetic properties (a saturation magnetization of 8.5 emu g(-1)), and nanoscale spherical morphology (average diameter around 600-700 nm). Besides, the formed Fe3O4 nanocrystals were well dispersed in the large SiO2 particles, and their superparamagnetic property was measured. The above features made these porous Fe3O4@SiO2 composite nanoparticles attractive candidates for adsorption and catalysis. We selected an organic dye, methylene blue, as a model adsorbate to investigate their adsorption performance, and adsorption experiments suggested their large adsorption capacity, easy magnetic separation, and good recyclability performance. This work not only provides a facile way for the fabrication of porous magnetic silica particles but also affords a platform to prepare other functional particles based on POSS.