Bulk nanoporous materials

This article reviews the synthesis, characterization, and applications of rare earth oxide and snlphide nanomaterials. Special focus is placed on nanoparticulate materials and the description on nanoscale films and bulk nanoporous materials are intentionally excluded. In the first section, the synthesis methods of nanoparticles in general are reviewed, and examples of the production of rare earth oxides and sulphides are presented. The second section deals with the applications of rare earth oxides and sulphides, and they are discussed in relation to the unique properties of nanoscale particles. 

Fig. 9 Schematic representation of three approaches to generate nanoporous and meso-porous materials with block copolymers, a Block copolymer micelle templating for mesoporous inorganic materials. Block copolymer micelles form a hexagonal array. Silicate species then occupy the spaces between the cylinders. The final removal of micelle template leaves hollow cylinders, b Block copolymer matrix for nanoporous materials. Block copolymers form hexagonal cylinder phase in bulk or thin film state. Subsequent crosslinking fixes the matrix hollow channels are generated by removing the minor phase, c Rod-coil block copolymer for microporous materials. Solution-cast micellar films consisted of multilayers of hexagonally ordered arrays of spherical holes. (Adapted from [33])...

Specifically, this volume focuses on the synthesis, processing, and structural tailoring of nanocrystalline and nanoporous materials. Nanocrystalline materials possess unique hybrid properties characteristic of neither the molecular nor the bulk solid-state limits and may be confined in nanometersized domains in one, two, or three dimensions for unusual size-dependent behavior. Nanoporous materials, characterized by well-defined pores or cavities in the nanometer size regime and controlled pore diameter and structure, give rise to unique molecular sieving capabilities and ultrahigh internal surface areas. Nanoporous structures also act as hosts and templates for the fabrication of quantum dots and quantum wires. 

Nanomaterials represent today s cutting edge in the development of novel advanced materials, which promise tailor-made functionality for unique applications in all important industrial sectors. Nanomaterials can be clusters of atoms, grains 100 nm in size, fibers that are less than 100 nm in diameter, films that are less than 100 nm in thickness, nanoholes, and composites that are a combination of these. In other words, it implies that the microstructures (crystallites, crystal boundaries) are nanoscale [1]. Nanomaterials include atom clusters, nanoparticles, nanotubes, nanorods, nanowires, nanobelts, nanofilms, compact nanostructured bulk materials, and nanoporous materials [2]. Materials in nanosize range exhibit... 

Nanoporous materials can be classified by pore geometry (size, shape, and order) or distinguished by type of bulk materials. Nanoporous... 

We first discuss GCMC results for Ar and water on the effect of the pore morphology (cylindrical, ellipsoidal, and constricted pores) and topology (Vycor) on the temperature dependence of capillary condensation hysteresis in nanoporous materials. In Figure 3, we plot the relative decrease of the hysteresis critical temperature, Tcc, with respect to the bulk critical temperature, 7 ", as a function of the pore size Ro (reduced to the size of the adsorbate... 

This publication established that crosslinking of the polystyrene was not necessary to support the pore structure in monolith nanoporous samples, that mild chemical degradation of an aliphatic polyester is a practical methodology for the generation of bulk porous samples, and that the hydroxyl group derived from the juncture of the PS-PLA material decorated the pore walls of the material. 

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