Syntheses Of Novel Mesoporous Carbon-based Materials By The Self-assembly Approach

Supramolecular aggregate's self-assembling approach has derived diverse mesostructured inorganic solids. The synthesis of mesoporous polymeric and carbonaceous materials and the derived hybrid carbons are now attracting resesrch interested.In this thesis, we have prepared novel mesoporous carbonaceous materials by superamolecular aggregates self-assemblely and studied their mesostructures and morphologis; we have synthesized hybrid mesoporous carbonaceous materials and investigated their preliminary applications.The thesis is composed of six chapters. The first chapter is a detailed review on supramolecular aggregate's self-assembling for rational controlled synthesis of mesoporous polymers and carbons.Chapter 2 describes the direct triblock-copolymer-templating synthesis of highly ordered fluorinated mesoporous carbon". The organic precursors are phenol, formaldehyde and a functional monomer of p-fluorophenol, and the organic structure directing agent is triblock copolymer Pluronic F127. Characterizations using XRD, TEM, Raman, FT-IR and nitrogen adsorption techniques reveal that the fluorinated carbons possess highly ordered mesostructures, high surface areas (693– 998 m2/g), large pore sizes (3.0– 4.3 nm), large pore volumes (0.43– 0.70 cm3/g) and C-F covalent bonds after high-temperature carbonization at 900 oC. Various mesostructures such as 2D hexagonal and 3D body-centered cubic structures can be synthesized by simply tuning the ratios of p-fluorophenol/phenol or phenol/triblock copolymer. The fluorinated mesoporous carbon modified GC electrode exhibits higher electron transfer rate than both pure mesoporous carbon FDU-15 modified and bare GC electrodes. These results further suggest the fluorination of mesoporous carbons and the potentials for fluorinated mesoporous carbons in electrocatalytic reactions.Ordered mesoporous crystalline C–TiO2 nanocomposites with high titania contents. The direct-triblock-copolymer-templating method is also demonstrated to synthesize ordered mesoporous crystalline C–TiO2 nanocomposites by using phenolic resin and acid-base pairs (acidic TiCl4 and basic counterpart Ti(OC4H7)4) as carbon and titanium sources, respectively. The nanocomposites possess high surface areas (207– 274 m~2/g), large pore sizes (3.2– 4.4 nm), large pore volumes (0.15– 0.25 cm~3/g), highly crystalline anatase pore walls which are"glued"by amorphous carbon. The titania content is as high as 87 wt%. Mesoporous crystalline C–TiO2 composites favors the immobilization of proteins.In Chapter 4, blending surfactants, namely triblock copolymer F127 and reversed triblock copolymer 25R4 are used as the structure directing agent for the synthesis of mesoporous carbon. The addition of 25R4 has great influence on both the mesostructure and morphology of the products. With the increase of the amounts of 25R4, the VH/VL value for the system decreases, resulting in the mesostructure transformation from 3D Im3m to the 2D p6mm structure, and the morphology from tile-like to curly sheet.In Chapter 5, supported Silcalite-1/mesoC composites are prepared by in situ crystallization of ordered mesoporous carbon/silica nanocomposite in the presence of organic zeolitic template TPAOH. Micron-sized Silicalite-1 crystals are dispersed on the external surface of mesoporous carbon. The loading amount of Silicalite-1 is about 20 wt%.