Preparation And Characterization Of Novel Amphiphilic Single-Walled Carbon Nanotubes

As single-walled carbon nanotubes (SWNTs) has excellent optical, electronic, mechanical, magnetic properties, SWNTs has attracted much attention of scientists since been found. However, SWNTs are insoluble in all solvents due to intermolecular forces influence that hold them together, forming bundles. These greatly limit the yield of usable material and interfere with exceptional properties of SWNTs. So the current research focuses on improving the dispersibility of SWNTs in solvent by a modified method. Meanwhile, we also achieved the functionalization of SWNTs when modifying SWNTs. We mainly researched introducing polyphenyl and azide-polyethylene glycol-thiol to SWNTs by the strategy of covalent modification in this paper. So we prepared a novel amphipathic SWNTs. We also introduced the group of thiol to surface of SWNTs at the same time. This laided the foundation for the SWNTs combining with metal nanoparticles or biological molecules. The specific studies are as follows:1. We successfully synthesized the compound of polyphenyl with two functional groups of alkynyl at the rim by Sonogashira cross-coupling reaction, D-A addition reaction and alkynyl group deprotection reaction. The polyphenylene was characterized by IR, NMR and high resolution mass spectrum.2. We created a new method of preparation heterbifuctional polyethylene glycol derivative. The functional polymer of azide-polyethylene glycol-thiol was successfully synthesized by selective substitution reaction and hydrolysis reaction, characterized by IR, NMR and GPC..3. Firstly, we introduced polyphenyl to SWNTs with by the approach of covalent modification. As the compound of polyphenyl had two groups of alkynyl, this effectively achieved a high group density in the surface of SWNTs. On that basis, we successfully introduced amphiphilic azide-polyethylene glycol-thiol to SWNTs and gained amphiphilic SWNTs containing thiol in surface. The functionalized SWNTs were characterized by thermal gravimetric (TGA), FTIR, Raman specotroscopy, Elemental analysis. All of results demonstrated that we successfully obtained amphiphilic single-wall carbon nanotubes. Meanwhile, we find that functionalized SWNTs had well dispersibility and stability in organic solvent and water. So this had laid a good foundation for the further application of SWNTs.