The organic-organic self-assembly of phenolic resins and triblock copolymers, under acidic conditions, was used to synthesize ordered mesoporous carbons (OMCs) and carbon-based materials. The adsorption and structural properties of these materials were thoroughly studied by nitrogen adsorption, thermogravimetry, XRD and STEM.
The first part of this work provides an insight into the self-assembly process under acidic conditions and shows that both the adsorption and structural properties of the polymer-templated OMCs can be easily tuned by varying the synthesis parameters such as the copolymer/carbon precursor ratio, acid concentration, and temperature.
The next part covers the organosilane-assisted soft-templating synthesis of OMCs. The effect of the size, structure and concentration of the organosilane used on the mesostructure formation is discussed. In the case of small organosilanes, such as tetraethyl orthosilicate (TEOS), it was possible to obtain uniform silica-carbon mesostructures even with high TEOS loadings. Also, much larger organosilanes such as tris(3-trimethoxysilylpropyl) isocyanurate were used, which resulted in OMCs doped with N and Si heteroatoms.
Another chapter of this dissertation is devoted to the incorporation of inorganic nanoparticles into carbon mesostructures. Specifically, metal or metal oxide nanoparticles in the form of colloidal solutions can be added to the synthesis mixture. This strategy was demonstrated for the synthesis of mesostructured carbon-based composites with silica and alumina nanoparticles and crystalline alumina nanosheets.
The final part of this dissertation is devoted to the enlargement of the specific surface area of the aforementioned carbons and carbon-based composites. It was shown that the surface area of these materials can be increased by adding TEOS into the synthesis of carbons in order to generate additional microporosity, and/or by post-synthesis activation of the resulting carbons with KOH, carbon dioxide or steam. A combination of this strategy with colloidal templating can be used to obtain hierarchically porous carbons with high surface area, at least two types of mesopores (generated by using block copolymer and colloidal silica templates) and enhanced microporosity (achieved by TEOS-assisted synthesis and/or post-synthesis activation).