Preparation of magnetically recoverable mesoporous silica nanocomposites for effective adsorption of urea in simulated serum

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2018-10, Vol.91, p.22-31
• Main Authors: Juang, Ruey-Shin, Chien, Chu-Chun, Yao, Chao-Ling, Yu, Ssu-Han, Sun, An-Cheng
• Format: Article
• Language: English
• Subjects: Cytotoxicity test; Magnetic nanocomposites; Mesoporous silica; Simulated serum; Urea adsorption
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2018.05.022

•Magnetic SBA-15/Fe3O4 nanocomposites were fabricated by chemically binding Fe3O4 nanoparticles onto SBA-15.•Pore volume of SBA-15/Fe3O4 was not notably reduced because Fe3O4 particles were merely coated on the surface of SBA-15.•Mesoporous SBA-15 provided up to two oxygen sites through hydrogen bonding to catch urea molecules.•SBA-15/Fe3O4 nanocomposites were synthesized as magnetically controllable hemoadsorption materials. In this study, SBA-15/Fe3O4 nanocomposites were prepared by conjugating Fe3O4 nanoparticles to mesoporous silica SBA-15 particles as magnetically recoverable adsorbents. The physicochemical and magnetic properties of bare and as-prepared samples were characterized using the X-ray diffractometer, transmission electron microscope, Fourier transform infrared spectroscope, porosimeter, and vibrating sample magnetometer. The performance of SBA-15, Fe3O4, and SBA-15/Fe3O4 nanocomposites for adsorption removal of uremic toxin urea in simulated serum was compared at 25 and 37 °C. Except for Fe3O4, both SBA-15 and SBA-15/Fe3O4 showed a high and equivalent adsorption ability for urea. Although the surface area of SBA-15/Fe3O4 nanocomposites decreased from 1167 m2/g (bare SBA-15) to 311 m2/g, the pore volume of SBA-15/Fe3O4 was not greatly decreased because most of Fe3O4 nanoparticles were coated onto the surface of SBA-15 particles. The adsorption mechanism of urea on SBA-15/Fe3O4 was proposed. Finally, the cytotoxicity of SBA-15/Fe3O4 nanocomposites before and after urea adsorption for fibroblast L929 cells was studied. [Display omitted] The following shows the adsorption mechanism of urea on SBA-15/Fe3O4 (left side). The mesoporous silica SBA-15 can provide up to two oxygen adsorption sites for urea through hydrogen bonding. The connection between SBA-15 and magnetic Fe3O4 nanoparticles just offers an easy way for attracting by applied magnetic field (right side). Therefore, urea can be easily trapped and removed from simulated serum and water samples.