Synthesis and functionalization of magnetite nanoparticles with different amino-functional alkoxysilanes

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:324

Article

Bini, Rafael A.¹  Marques, Rodrigo Fernando C.²  Santos, Francisco J.¹  Chaker, Juliano A.³  Jafelicci, Miguel, Jr.¹ 

[1] Sao Paulo State Univ UNESP, Lab Magnet Mat & Colloids, Inst Chem, Caixa Postal 355, BR-14800900 Araraquara, Brazil

[2] Alfenas Fed Univ, Inst Sci & Technol, BR-37701100 Pocos De Caldas, Brazil

[3] Univ Brasilia, FCE, BR-72220140 Brasilia, DF, Brazil

关键词: Magnetite;    Superparamagnetism;    Magnetic measurement;    Surface functionalization;    Electrokinetic measurement;   

DOI  :  10.1016/j.jmmm.2011.08.035

来源: Elsevier

【 摘 要 】

Superparamagnetic iron oxide (SPIO) nanoparticles show great promise for many biotechnological applications. This paper addresses the synthesis and characterization of SPIO nanoparticles grafted with three different alkoxysilanes: 3-aminopropyl-triethoxysilane (APTES), 3-aminopropyl-ethyl-diethoxysilane (APDES) and 3-aminopropyl-diethy-ethoxysilane (APES). SPIO nanoparticles with an average particle diameter of 10 nm were prepared by chemical sonoprecipitation. As confirmed by Fourier transform infrared (FTIR) spectroscopy, silylation of these nanoparticles occurs through a two-step process. Decreasing the number of alkoxide groups reduced the concentration of free amino groups on the SPIO surface ([SPIO-NH2] APTES > APDES > APES). This phenomenon results from steric contributions and the formation of H-bonded amines provided by the ethyl groups present in the APDES and APES molecules. A simulation of SPIO nanoparticles in a saline physiologic solution shows that the ethyl groups impart larger steric stability onto the ferrofluids, which reduces aggregation. The magnetization (M) versus magnetic field (H) curves show that the synthesized iron oxide nanoparticles display superparamagnetic behavior. The zero-field cooling (ZFC) and field cooling (FC) curves show that the changes in the blocking temperature depend on the alkoxysilane-functionalized particle surface. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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