| Carbon nanotubes (CNTs) have attracted considerable research interest in the past decade due to their excellent mechanical, unique electronic and thermal properties. Especially, CNTs own one-dimensional space structure and relatively higher surface area, it is possible to attain novel CNTs-based composites by immobilizing some substances onto them. Finally, CNTs would be used for photoelectrocatalysis and loading of various biomolecules or drugs.In this thesis, firstly, we summarized chemical modification of CNTs, magnet-targeted drug delivery system as well as CNTs-based drug delivery system. Then multi-walled carbon nanotubes (MWCNTs) /ferromagnetism nanohybrids were prepared and applied on anticancer drug. At last, MWCNTs/FeOOH nanocomposites were synthesized and used as adsorbent for removing Cr (Ⅵ) from waste water. The main contents were as follows:1. Preparation and surface modification of MWCNTs-based ferromagnetism hybridsIn the part, the synthesis technologies of MWCNTs-based magnet-targeted drug delivery carriers were studied and optimized. The MWCNTs/Fe3O4 composites were prepared by the means of co-precipitation method; The MWCNTs/Fe2O3 hybrids were obtained through calcining MWCNTs/β-FeOOH at 350℃for 3h. The Fe3O4 and Fe2O3 nanoparticles loaded on MWCNTs have smaller diameter, more symmetrical distributing and stronger magnetization, respectively. For the purpose of improving their dispersibility in water, holding back aggregation of magnetic particles and increasing their biocompatibility, MWCNTs-based ferromagnetic composites were further modified with polysaccharide (chitosan or alginate) via non-covalent method. The synthesized nanocomposites were studied and characterized by Fourier transform infrared spectrometer (FT-IR), X-ray powder diffractometer (XRD), Transmission electron microscope (TEM), Zetasizer and VSM etc. All these results suggested that the ferromagnetic nanoparticles obtained own smaller diameter and stronger magnetization.2. Loading and controlled release of anticancer drug (doxorubicine) from the MWCNTs-based ferromagnetic compositesOwing to structural similarity of doxorubicin (DOX) and CNTs, DOX was loaded successfully onto functionalized MWCNTs through simple mixed reaction in a pH 7.4 PBS buffered solution (normal physical environment). It was suggested that the driving force for the loading of DOX on MWCNTs might be attributed toπ-πstacking and electrostatic interaction. DOX was released slowly from MWCNTs in a pH 4.8 PBS buffered solution (lysosomal pH and the pH characteristic of certain tumor environments) due to its pH-sensitive character. The results showed that the MWCNTs/Fe3O4 and MWCNTs/Fe2O3 nanocomposites would have potential applications for targeted delivery and controlled release of anticancer drugs; Loading and release of DOX were studied through Ultraviolet spectrum (UV-vis) and Fluorescence spectrum (FL).3. Preparation and application for removing Cr (Ⅵ) from waste water of MWCNTs/FeOOH compositesThe preparative technique of MWCNTs/FeOOH was discussed in this part. The MWCNTs/FeOOH composites were prepared via simple co-precipitation method. Morphology and structure of the FeOOH nanomaterials loaded on MWCNTs were different by changing the experimental conditions (pH, Alkali, Concentration, Temperature, Inorganic anions). As MWCNTs and FeOOH each had stable chemical property, relatively high surface area and extra fine structure, the MWCNTs/FeOOH hybrids could be used as adsorbent to remove Cr (Ⅵ) from Chinese medicine solution through laboratory study. The structure and performance of the samples were studied by FT-IR, XRD, TEM, etc; Adsorptive capacity was conducted by coupled plasma spectrometer.
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