Preparation Of Cyclodextrin Modified Magnetic Nanoparticles And Its Applications

The magnetic nanoparticles (MNPs) own unique magnetic properties, excellent biocompatibility, activity of catalysis and low toxicity, which have enabled a wide spectrum of applications. It is widely known that cyclodextrin (CD) can form inclusion complexes with a wide variety of organic compounds in its hydrophobic cavity through host-guest interactions. When the MNPs modified with CD, it is possible to obtain the new materials simultaneously possessing the unique properties of MNPs (superparamagnetism and electrocatalytic) and CDs (high supramolecular recognition and host-guest inclusion capability) through combining their individual characteristics. In this paper, three novel CD modified magnetic nanoparticles are synthesized, and their properties and applications are also studied.This dissertation consists of four chapters:Chapter1:This part introduced the characteristics, surface modifications and applications of magnetic nanoparticles. The properties, molecular recognition and application of the cyclodextrins are depicted in brief. The research progresses of cyclodextrin modified Fe3O4magnetic nanoparticles are also reviewed in detail.Chapter2:A kind of novel surface-functionalized magnetic nanoparticles (CD-MNPs) is fabricated by the Fe3O4nanoparticles surface modification with6-TsO-β-CD. First the magnetite nanoparticles are synthesized by coprecipitaion method, then hydrolysis of APTES formed a layer of-NH2functionalized nanoparticles. Finally,6-TsO-β-CD grafted onto the surface of magnetic nanoparticles. The architecture has been characterized by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), vibration sample magnetometer (VSM) and thermogravimetric analysis (TGA), which confirmed that cyclodextrins have been effectively functionalized on the surface of Fe3O4nanoparticles. The grafted β-cyclodextrin on the Fe3O4nanoparticles contributed as a modified electrode for detecting uric acid with cyclic voltammograms.Chapter3:A new magnetic nanomatreials (CD-NH2-MNPs) was synthesized by grafting6-TsO-β-CD on-NH2modified Fe3O4nanoparticles. The as-synthesized magnetic nanoparticles were characterized by many methods. The feasibility of using CD-NH2-MNPs as modified electrode for selective catalysis of dopamine based on inclusion and molecular recognition was demonstrated. The stability of the modified electrode was excellent.Chapter4:The Fe3O4/SiO2/MAHCD magnetic nanocomposites are synthesized in this part. Firstly, the Fe3O4magnetite nanoparticles are coated SiO2by modified Stober method. Then, MAH-CD grafted onto the surface of magnetic nanoparticles via EDC. Finally, the new nanocomposites are characterized by many methods. The as-synthesized magnetic nanoparticles were used as nano-absorbents for removal of Neutral Red (NR) from aqueous solution. The equilibrium data for NR adsorption are fitted well by Freundlich isotherm model.