Nanosphere templated materials

In general, microgels obtained by radiation methods can be used in various applications in the same way as conventional synthesized systems, e.g., as drug delivery templates, for encapsulation, or as microreactors [29, 30], PAAm for example can be used as template material to synthesize hollow cadmium selenide nanospheres [24], and PVP can be used for the incorporation of ferromagnetic nanoparticles to obtain magnetic hydrogel microspheres [13],... 

Nanospheres are hollow nanosized particles (Figure 47.1C) that can be prepared by microemulsion polymerization or covering the surfaces of colloidal templates with thin layers of the desired material followed by selective removal of the templates (Hyuk Im et al., 2005). The carboxylated polystyrene nanospheres (20 nm) were evaluated for drug delivery... 

Kirkendall Effect The Kirkendall effect is a phenomenon observed frequently in solid materials [38]. It refers to a vacancy counter diffusion process through an interface of two solid materials, metals in particular, to compensate the unequal material flow formation at the interface [38a]. In metals and metallic alloys, the vacancy is atomic defect, that is, empty lattice site. Combination of excess vacancies can lead to the formation of void within the fast-diffusion side of the interface [39]. While this phenomenon has been known for a very long time, synthesis of hollow nanostructures based on Kirkendall effect was realized fairly recently [40]. Ym studied the time evolution in the formation of hollow nanospheres and found that Kirkendall diffusion followed the Tick s law [41]. This means that the diffusion of atoms and vacancies is driven by the difference in atom concentration. Wu et al. synthesized hollow nanostructures of CoCuPt alloy catalyst by using Co nanoparticles as the sacrificial templates. For this trimetallic system, Co atoms diffused faster than those of Pt or Cu to form core-shell like Co CuPt hollow nanoparticles and then the CoCuPt hollow spheres (Fig. 2.10) [42]. 

Polystyrene nanospheres can be also used as a specific template for the preparation of nanocomposites with organic materials. In fact, the electropolymerization can be carried out within the voids of polystyrene nanospheres giving rise to RANI honeycomb films with desirable pore size, pore wall widths, and film thickness [245]. 

Underhill, R.S. and Liu, G.J. (2000b) Triblock nanospheres and their use as templates for inorganic nanoparticle preparation. Chemistry of Materials, 12,2082-2091. 

Various attempts are being made to tailor-make HSNS by manufacturing and applying different sacrificial templates, synthesis procedmes, parameter variations, and inner diameters and shell thicknesses of the nanospheres. A crucial issue will be how to assemble the HSNS together Into a practical, robust, and sustainable bulk material. It is emphasized that the future NIM may not be... 

Nanocapsules (hollow nanoparticles, nanospheres) are submicrometric colloidal objects composed of a liquid core surrounded by a thin silicone shell. The vesicle templating, solidification in emulsion and solidification of vesicles are the main methods for preparation of the silicone nanocapsules. The vesicle templating method is based on imprinting in the prepared materials the shape and size of the vesicles used as a template. Among the most popular templates are vesicles created from phospholipids (liposomes), double-tailed... 

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