Hydrophilic Modification Andproperties Of Multi-walled Carbon Nanotubes

Carbon nanotube (CNT) as an ideal one-dimensional quantum material, exhibitsmany favourable properties, such as mechanical, electrical, thermal and opticalproperties, ect. In recent years, CNTs become one of the hottest research objects, andmore and more researchers focus on the design of composite materials. Although thephysical and chemical properties of carbon nanotubes are very excellent, the largerspecific surface area and higher specific surface energy of CNTs result in the seriousaggregation. Thus, the applications are greatly limited in many fields. For this reason,it is significant to modify CNTs functionally.In this work, the oxidized carbon nanotubes (OCNT) are firstly prepared by theHummer's method, and then reduced with glucose to obtain RCNT. Thecharacterizations show that OCNT has many oxygen containing groups, but most ofthe oxygen containing groups in RCNT are disappeared. Compared to CNTs, OCNTand RCNT have good dispersion in water. As the fillers, CNTs, OCNT and RCNTwith different contents were respectively added to the plasticizing starch (PS) matrix,and then these composite films were prepared by the casting method. PS/OCNT andPS/RCNT composites are more uniform than PS/CNT composite. Therefore,PS/OCNT and PS/RCNT composites can effectively improve mechanical propertiesand water vapor permeability of the plasticizing starch film. In addition, membranematerials also have strong conductive ability.In this work, the cyclodextrin loading carbon nanotubes (RCNT-CD) is alsofabricated by the method of hydrazine hydrate reduction. A series of characterizationsshow that the ?-cyclodextrin (?-CD) successfully loaded to the surface of CNTs, andthe stability of RCNT-CD in the water is very good. Then, the RCNT-CD andmethylene blue (MB) aqueous solution modify glassy carbon electrode (GCE)together, and then selectively recognize the chiral molecule: D-tartaric acid andL-tartaric acid. The electrochemical response of the electrode is analyzed by cyclicvoltammetry curves. The results show that the prepared sensor is performed inqualitative and quantitative chiral analysis. The modified electrode not only has anexcellent electrochemical performance of CNTs, but also makes full use of themolecular recognition of CD. Iron oxide particles were attached to RCNT-CD inpreparation of magnetic RCNT-CD (RCNT-CD/Fe3O4). RCNT-CD/Fe3O4is used for the adsorption of methylene blue dye in wastewater. Since iron oxide particles areattached to the RCNT-CD, the nanocomposite has good magnetic properties.Adsorption test of RCNT-CD/Fe3O4showed that it is a good adsorbent for methyleneblue. The process of adsorption conforms to the pseudo-second-order model and theisotherm data followed the Langmuir model, and it is a spontaneous and endothermicprocess. When the adsorption is completed, the adsorbent can be magneticallyseparated from the solution.