Hierarchical nanocomposites preparation

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Continuous mesoporous carbon thin films were fabricated by direct carbonization of sucrose-silica nanocomposite films and subsequent removal of the silica [236]. The mesoporous carbon film with uniform and interconnected pores had a surface area of 2603 mVg and a pore volume of 1.39 cmVg. Subsequently, nanoporous carbons with bimodal PSD centered at about 2 and 27 nm in diameter were prepared by using both the TEOS-derived silica network and the colloidal silica particles as templates [237]. Figure 2.33 illustrates the preparation pathway. The pore sizes of the carbon are determined by the sizes of the added silica particles and the silica network. As the colloidal silica particles are commercially available with different diameters (e.g., 20 to 500 nm), this dual template synthesis process provides an efficient route to preparing nanoporous carbons with a controllable hierarchical pore structure. 

A different approach to the synthesis of nanosized macromolecules through hierarchical self-assembly is based on Layer-by-Layer (LbL) chemistry. LbL allows the deposition of ultra thin films whose thickness can be controlled by the chemical structure of the molecules and number of deposited layers. The interactions between layers can be ionic, covalent, hydrogen-bonding, and charge-transfer, depending upon the nature of the polymer used in the preparation.The layer-by-layer assembly of an electroactive polymer nanocomposite thin film of cationic linear poly(ethyleneimine) and Prussian Blue nanoparticles, has been exploided... 

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