Preparation And Modification Of Carbon Nanotube-based Magnetic Composite Particles

The composite particles of CoFe2O4 loading on carbon nanotubes (CNTs) were prepared through polyol method in this paper. After modifying these particles, CNTs-based composite vectors with magnetic granule of which had narrow size distribution, monodispersibility, strong magnetic responsiveness and plenty of functional groups were prepared. This work provided detailed theory and experimental basis for the application of CNTs-based composite particles in magneticly targeted therapy of cancers. The details were described as below:Firstly, CoFe2O4/CNTs magnetic composite particles were prepared through high temperature-polyol method by using spinel type ferrite CoFe2O4 as inorganic magnetic material, CNTs as one-dimensional template and triethyleneglycol as reaction medium.The results showed that the coating was dense and uniform, the particles had strong magnetic responsiveness (Ms=44.8 emu-g-1) and superparamagnetism.Secondly, SiO2/CoFe2O4/CNTs magnetic composite particles were prepared by improved Stober method using TEOS as a modifier.The thickness of the coating layer of SiO2 was moderate and uniform.Thirdly, the amino-modified SiO2/CoFe2O4/CNTs magnetic composite particles were prepared by functionalizing using y-aminopropyl trimethoxysilane (APTES). The functional groups, compositions and magnetic properties of modified composite particles were characterized and analyzed by XRD, FTIR, XPS, VSM, et al. The results showed that the particles still had superparamagnetism, Ms=29.6 emu-g-1Finally, the folic acid was grafted on the surface of amino-modified SiO2/CoFe2O4/CNTs magnetic composite particles through condensation reaction, then Floate-SiO2/CoFe2O4/CNTs composite particles were prepared. The particles were characterized and analyzed by XRD, FTIR, XPS, VSM, et al. The results showed that the folic acid was grafted on the surface of amino-modified SiO2/CoFe2O4/CNTs successfully and the Floate-SiO2/CoFe2O4/CNTs composite particles retained well magnetic responsiveness and superparamagnetism (Ms=22.5 emu-g-1). It laid the foundation for the application in the magneticly targeted therapy of cancers.