Nanosized Mesoporous Carbon Materials:Synthesis, Property And Application

Nanostructured materials have attracted extensive attention of researchers due to their great potential applications. Carbon nanostructures, such as fullerenes, carbon nanotubes and graphene, are materials of increasing interest due to their excellent electronic properties as well as their good physical and chemical properties. Ordered mesoporous carbon materials are one special kinds of nanomaterials. Due to their various framework compositions, fascinating pore architectures, large porosities and diverse morphologies, ordered mesoporous materials have triggered substantial research interests in material science, and possess great potential for the applications in energy, environment and human health fields. However, nanosized mesoporous carbon nanostructures, which could combine the advantages of mesopores and nanomaterials together, are quite useful but hard to be realized.This thesis focus on exploring feasible synthesis routes for nanosized mesoporous carbon materials and investigating suitable applications for them.0-D mesoporous carbon nanospheres,0-D mesoporous carbon nano-hemispheres,0-D dual pore mesoporous nanospheres,2-D mesoporous graphene nanosheets, and 2-D mesoporous polymers have been farbricated for the first time by organic-organic self-assembly procedure in solution phase. These nanostructured mesoporous carbon materials show amazing properties:they are excellent drugs nanocarriers or good energy storage materials.In chapter 2, we demonstrate a novel low-concentration hydrothermal route to synthesize highly ordered body-centered cubic (Im 3 m) mesoporous carbon nanopaticles with spherical morphology and uniform size. Commercial available triblock copolymer Pluronic F127 was employed as a template and phenolic resol as a carbon source. A low-concentration (～10-7 mol/L surfactant concentration) controlled hydrothermal treatment was carried out to obtain the nanostructure and confine the particle size. The ordered mesostructures were retained while the spherical diameters were tuned from 20 to 140 nm by simply varying the reagent concentration. Small-sized nanosphere with a diameter of ～20nm, of which the boundary approaches to only one mesostructural unit cell, is observed for first time. This method may reveal a possible alternative to "classical" methods for the preparation of carbon nanostructures and in some cases, the only viable synthetic route toward certain carbon nanostructures. The obtained mesoporous carbon nanospheres show not high cytotoxicity, good cellar permeability and high drug capacity, which is greatly potential in prospected application of cellar delivery and cell imaging.In chapter 3, we demonstrate the synthesis of dual pore mesoporous, rattle-like uniform carbon@silica core/shell nanospheres for the first time. Monodispersed mesoporous phenolic polymer nanospheres with a uniform diameter of ～120 nm are first prepared by a low concentration hydrothermal method via an organic-organic assembly using amphiphilic triblock copolymer Pluronic F127 as a template and the resultant nanosperes are used as a core for the further growth of the core-shell mesoporous nanorattles. The mesoporous nanospheres have a uniform diameter of 200 nm and dual ordered mesopores of ～3.1 and 5.8nm. Benefited from the hierarchical mesostructure, dual pore mesochannels and amphiphilicity of the hydrophobic carbon cores and hydrophilic silica shells, the multi-drug combination therapy with cis-Pt and paclitaxel is demonstrated for the treatment of human ovarian cancer. Our novel nanocarriers loaded with both of the drugs can kill over 50% of target cells, showing excellent treatment effect even for the drug resistance human ovarian cancer cells.In chapter 4, ordered mesoporous carbon nanopaticles with various morphologies have been synthesized by a novel low-concentration hydrothermal route. Commercial available triblock copolymer Pluronic F127 was employed as a template and phenolic resol as a carbon source. By using monodispersed mesoporous phenolic polymer nanospheres with a uniform diameter of～120 nm as a core, silica coated core-shell structures have been further formed. Monodispersed mesoporous carbon hemi-nanospheres have been fabricated via the tension effect between the carbon core and silica shell. The mesoporous hemispheres are 130 nm in length and 60 nm in thickness, and they can disperse well in water, which is greatly potential in prospected application of cellar delivery.In chapter 5, we demonstrate a new solution-deposition method to synthesize an unprecedented type of two-dimensional (2D) ordered mesoporous carbon nanosheets, via a controlled low-concentration monomicelle close packing assembly approach. These obtained carbon nanosheets possess only one layer of ordered mesopores laid on the surface of a substrate, typically the inner walls of anodic aluminum oxide (AAO) pore channels, and can be further converted into mesoporous graphene nanosheets by carbonization. The atomically flat graphene layers with mesopores provide high surface area for lithium ion adsorption and intercalation, while the ordered mesopores perpendicular to the graphene layer enable efficient ion transport as well as volume expansion flexibility, thus representing a unique orthogonal architecture for excellent lithium ion storage capacity and cycling performance. Lithium ion battery anodes made of the mesoporous graphene nanosheets have exhibited an excellent reversible capacity of 1040 mAh/g at 100 mA/g, and they can retain at 833 mAh/g even after numerous cycles at varied current densities. Even at a large current density of 5 A/g, the reversible capacity is retained around 255 mAh/g, larger than most of other porous carbon based anodes previously reported, suggesting a remarkably promising candidate for energy storage.In chapter 6, we demonstrate a novel method for in-situ growth of 2-D mesoporous carbon/polymer thin films on various substrate. The in-situ growth procedure is feasible on several kinds of substrates from inch scale to nano size. The 2-D mesoporous thin film could be planted on nanocube, nanodisc, nanowire, nanorod or on flexible plane. This growth procedure could be operated not only on the surfaces of metal oxides but also on the inert carbon surfaces. The 2-d mesoporous carbon thin film and metal oxide composite should be promising candidate for energy storage.In Chapter 7, the whole thesis is summarized.