Preparation And Characterization Of Chiral Mesoporous Carbonaceous Nanofibers And N-doped Carbonaceous Nanotubes

Chiral mesoporous carbonaceous have attracted numerous attention due to their high surface area, large pore volume, tunable pore sizes and optical activity. They will be applied in separation, catalysis, energy storage and electrochemical capacitors. Preparation of chiral mesoporous carbonaceous nanomaterials using the supramolecular templating method was studied in the thesis.Firstly, mesoporous C/SiO2 nanofibers were prepared by the carbonization of mesoporous 1,2-ethylene-brideged polybissilsesquioxane which were prepared using cetyltrimethylammonium bromide,(S)-citronellol, and 1,2-bis(triethoxysilyly)ethane. After removal of carbon or silica, silica nanofibers with lamellar mesopores or isolated carbon particles were obtained, respectively. The results indicated that the mesoporous C/SiO2 nanofibers were constructed by silica framework and isolated carbonaceous particles.Secondly, single-handed helical mesoporous carbonaceous nanofibers were prepared using the self-assemblies of L- and D-18Val11 PyBr as the templates, m-diphenol-formaldehyde resin as the carbon source, and tetraethoxylsilane as the silica source. The mesopores were formed by removing silica. The circular dichroism spectra indicated that the carbonaceous samples exhibited optical activity. Finally, N-doped straight and single-handed helical carbonaceous nanotubes were obtained using the L- and D-18Val11PyPF6 as the templates and 3-aminophenol-formaldehyde resin as the carbon source. The circular dichroism spectra also indicated that the carbonaceous N-doped nanotubes exhibited optical activity.The results shown here lay a foundation for the application of chiral carbonaceous nanomaterials in asymmetric catalysis and enatioseparation.