Studies On Preparation And Properties Of Novel Magnetic Nano Functionalized Materials

In recent years, many novel magnetic nanostructured functional materials have been developed from the perspective of multi-crossed disciplines. Among which, magnetic targeting drug carrier, magnetic fluid and magnetic nano-composite have become relatively outstanding sorts and research hot spots. Although the research of these materials has been deepened and the application area has been broadened constantly, there still exits some problems worth to be further explored. As to magnetic targeting drug carrier, the main problem still lies in the selection of propping materials and the preparation method of novel sorts with perfect performances and extensive applications. In the respect of magnetic fluid and magnetic nano-composite, how to implement the homogeneous dispersion of magnetic nanoparticles in carrier liquid and polymer matrix in the preparation of stable and exceptional nanostructured functional materials remains to be the primary and difficult point. In this research, some new kinds ofβ-cyclodextrin-functionalized Fe₃O₄ magnetic nanoparticles were designed and developed as magnetic targeting drug carriers and their relative properties were studied. Monooctadecyl maleate as polymerizable surfactant was utilized to modify Fe₃O₄ magnetic nanoparticles. Polymerizable magnetic fluid was obtained by directly dispersing modified Fe₃O₄ magnetic nanoparticles into styrene monomer and PS/Fe₃O₄ magnetic nano-composite was further prepared by the free radical polymerization of the magnetic fluid. The relative properties of both the magnetic fluid and the nano-composite were investigated. The research work offered new ideas and ways on how to exploit novel magnetic nanostructured functional materials and expanded the relative application areas. The main research and results of the contribution are summarized as follows:Carboxymethyl-β-cyclodextrin (CM-β-CD) with carboxyl substitution of 1.2 and 7.3 was synthesized, and utilized to prepare CM-β-CD-modified Fe₃O₄ magnetic nanoparticles in water and DMF medium, respectively. The morphology, structure and component of CM-β-CD-modified Fe₃O₄ magnetic nanoparticles were characterized by TEM, FTIR, XRD, DLS, TG and their relative properties were also studied. It is more ideal for the Fe₃O₄ magnetic nanoparticles to be modified by CM-β-CD with carboxyl substitution of 1.2 in water medium. In such condition, the prepared CM-β-CD-modified Fe₃O₄ nanoparticles are roughly spherical and their diameter rang from 10¹5 nm. The weight percentage of CM-β-CD in CM-β-CD-modified nanoparticles prepared is estimated to be about 8.2%. The prepared CM-β-CD-modified nanoparticle with saturation magnetization of 68.7emu/g exhibit both good superparamagnetic properties and stable dispersibility in water. In optimized condition, the curcumin loading content and entrapment ratio for the prepared nanoparticles was detected as 21.7μg/mg and 43.4% respectively. The drug loading nanoparticles exhibited rapid drug release in 4 hours and slow drug release in the followed 26 hours in vitro releasing experiment.Cross-linkedβ-cyclodextrin polymer/Fe₃O₄ composite nanoparticles were prepared via cross-linking reaction on the surface of CM-β-CD-modified Fe₃O₄ magnetic nanoparticles dispersed inβ-cyclodextrin alkaline solution by using epichlorohydrin (EP) as a crosslinking agent. The morphology, structure and component ofβ-cyclodextrin polymer/Fe₃O₄ composite nanoparticles were characterized by TEM, SEM, FTIR, XRD, DLS, TG and their relative properties were also studied. The result indicats that the prepared cross-linkedβ-cyclodextrin polymer/Fe₃O₄ composite nanoparticles with typical core-shell structures are roughly spherical, and their diameter rang from 20⁴0 nm. The weight percentage of cross-linkedβ-cyclodextrin polymer shell in the composite nanoparticles is about 28.0% and the prepared compsite nanoparticles with saturation magnetization of 52.0emu/g possess good superparamagnetic properties as well as stalbe dispersibility in water. Compared with CM-β-CD-modified Fe₃O₄ magnetic nanoparticles, the curcumin loading content and entrapment ratio for the prepared composite nanoparticles was promoted to 86.9μg/mg and 72.4% respectively in optimized condition. The drug loading composite nanoparticles exhibited better drug release properties in vitro releasing experiment.Fe₃O₄ magnetic nanoparticles were modified by 3-glycidoxypropyltrimethoxysilane (GTMS) which have reactive epoxy end groups andβ-cyclodextrin grafted GTMS-modified Fe₃O₄ magnetic nanoparticles were prepared by conjugatingβ-cyclodextrin onto GTMS-modified Fe₃O₄ magnetic nanoparticles via reaction between epoxy groups on the surface of GTMS-modified Fe₃O₄ magnetic nanoparticles and hydroxyl groups ofβ-cyclodextrin. The morphology, structure and component of the prepared Fe₃O₄ magnetic nanoparticles were characterized by TEM, FTIR, XRD, DLS, TG and their relative properties were also studied. The result shows that the prepared nanoparticles are roughly spherical and their diameter rang from 10¹5 nm. The weight percentage of graftedβ-cyclodextrin in the prepared nanoparticles is about 2.2%. The prepared nanoparticles with saturation magnetization of 67.5emu/g possess superparamagnetic properties as well as stable dispersibility in water. In optimized condition, the adriamycin (ADM) loading content and entrapment ratio for the prepared nanoparticles was detected as 5.7μg/mg and 47.5%, respectively. The drug loading nanoparticles exhibited rapid drug release in the initial stage and slow drug release in the followed long time in vitro releasing experiment.MAH-β-CD was synthesized and Fe₃O₄ magnetic nanoparticles were modified byγ-methacryloxypropyltrimethoxy (MPS) which have reactive double carbon bonds. P(MAH-β-CD-co-AA)/Fe₃O₄ composite nanoparticles were prepared via free radical copolymerization of MAH-β-CD and acrylic acid on the surface of MPS-modified Fe₃O₄ magnetic nanoparticles. The morphology, structure and component of P(MAH-β-CD-co-AA)/Fe₃O₄ composite nanoparticles were characterized by TEM, FTIR, XRD, DLS, TG and their relative properties were also studied. The result indiates that the prepared composite nanoparticles with diameter ranged from 10-15 nm are roughly spherical. The weight percentage of grafted P(MAH-β-CD-co-AA) copolymer in the prepared nanoparticles is about 28%. The prepared composite nanoparticles with saturation magnetization of 60.0emu/g exhibited superparamagnetism as well as stable dispersibility in water. Compared withβ-cyclodextrin grafted GTMS-modified Fe₃O₄ magnetic nanoparticles, the curcumin loading content and entrapment ratio for the prepared composite nanoparticles was promoted to 93.8μg/mg and 78.2% in optimized condition. The drug loading composite nanoparticles exhibited rapid drug release in the initial stage and slow drug release in the followed long time in vitro releasing experiment.Monooctadecyl maleate as polymerizable surfactant was synthesized utilized to surface-modify Fe₃O₄ magnetic nanoparticles. A stable polymerizable magnetic fluid was obtained by directly transferring modified Fe₃O₄ magnetic nanoparticles from aqueous phase to styrene monomer. Polystyrene/Fe₃O₄ nano-composite was prepared via bulk polymerization of polymerizable magnetic fluid. The morphology, structure, stability, rheological and magnetic properties of prepared magnetic fluid and the morphology, structure, thermal stability as well as magnetic properties of prepared polystyrene/Fe₃O₄ nano-composite were studied, respectively. Result shows that Fe₃O₄ magnetic nanoparticles modified by monooctadecyl maleate with the diameter of about 7 nm can be homogeneously dispersed in the styrene monomer and fixed in the nano-composite without apparent aggregation during the procedure of polymerization. The prepared polymerizable magnetic fluid with good stability and magnetic rheology property is a sort of typical superparamagnetic materials according with inferior Bingham fluid pattern. Copolymerization occurred between styrene monomer and monooctadecyl maleate modified on the surface of Fe₃O₄ magnetic nanoparticles during the preparation of polystyrene/Fe₃O₄ nano-composite. Compared with polystyrene prepared under almost the same polymerization conditions, the thermal stability of polystyrene/Fe₃O₄ nano-composite is obviously improved and the composite is also a sort of superparamagnetic materials.