Preparation of Fe_3O_4@SiO_2@PAA multilayer core-shell structural composite microspheres and its dye adsorption performance

XU Peng;LIANG Xuguang;CAO Xiaoyong;LIU Songcan;WANG Liying;GAO Qinwei;College of Chemical Engineering,Nanjing Forestry University;Jiangsu Key Lab.for the Chemistry &Utilization of Agricultural and Forest Biomass;Nanjing Institute of Supervision &Testing on Product Quality;College of Forestry,Nanjing Forestry University;

multilayer core-shell structural;;composite microspheres;;dye;;adsorptive property

In the present study,Fe_3O_4 magnetic nanoparticles were fabricated by solvothermal method. Tetraethyl orthosilicate(TEOS) was used as precursor to fabricate a layer of SiO_2 on the surface of Fe_3O_4 nanoparticles. 3-(methacryloyl oxygen) trimethoxy silane(APTES) was used as silane coupling agent to modify the surface of SiO_2@ Fe_3O_4 with double carbon bonds,then Fe_3O_4/silicon dioxide/poly(acrylate acid)(Fe_3O_4@ SiO_2@ PAA) multilayer core-shell structural composite microspheres were prepared by cross-linking precipitation polymerization of acrylate acid and divinyl benzene monomers without the use of surfactants and stabilizers. The as-synthesized particles have been characterized by means of transmission electron microscopy( TEM),Fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA). The size of the prepared Fe_3O_4 nanoparticles was about 150-250 nm. The Fe_3O_4 nanoparticles exhibited good water-solubility and were successfully encapsulated by SiO_2 shell. The PAA was successfully grafted onto the surface of SiO_2 to form Fe_3O_4@ SiO_2@ PAA multilayer core-shell composite microspheres. The results of Fe_3O_4@ SiO_2@ PAA microspheres showed high performance in the adsorption of Rhodamine6 G and methylene blue. The 10-minute adsorption reached 1.04 mg/g and 1.14 mg/g.