Facile synthesis of ordered magnetic mesoporous gamma-Fe2O3/SiO2 nanocomposites with diverse mesostructures.
On the basis of a sol-gel process, a facile, low cost, and one-step approach for preparing ordered magnetic mesoporous gamma-Fe(2)O(3)/SiO(2) nanocomposites by an evaporation-induced self-assembly (EISA) approach is presented. Various mesostructured silica materials (P6mm or Im3m) incorporated with different amounts of iron oxide (n(Si)/n(Fe) = 9/1, 8/2, 7/3, respectively) were synthesized and characterized by XRD, TEM, N(2)-sorption analyses, and superconducting quantum interference device (SQUID) magnetometer. The HCl-leaching experiments together with TEM micrographs and nitrogen sorption analysis suggested that most of the gamma-Fe(2)O(3) domains of several nanometers were embedded in the silica walls, rather than dispersed in the mesopores, which could cause the significant pore clogging reported in some studies. The release behaviors of lysozyme from these magnetic porous nanocomposites were investigated for the possible application of drug targeting and control release. The influence of iron precursors was also studied and a possible mechanism was proposed. The hydrolysis of Fe(3+) ions under weakly acidic conditions and the induced formation of Si-O-Fe bonds may account for the synthesis of this kind of nanocomposite. These multifunctional nanostructured materials would have a wide range of applications in toxin removal, catalysis, waste remediation, and biological separation as well as novel drug-carrier technologies.
Wang
Yangang
Y
Lab for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, People's Republic of China.
Ren
Jiawen
J
Liu
Xiaohui
X
Wang
Yanqin
Y
Guo
Yun
Y
Guo
Yanglong
Y
Lu
Guanzhong
G
D000327:Adsorption; D005290:Ferric Compounds / Q000737:chemistry*; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D009113:Muramidase / Q000737:chemistry / Q000302:isolation & purification; D053761:Nanocomposites / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D044367:Phase Transition; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
D005290:Ferric Compounds; C000499:ferric oxide; D012822:Silicon Dioxide; D009113:Muramidase