Matrix encapsulated nanometals

Sonochemical Synthesis of Nanometals Encapsulated in a Carbon Matrix... 

There are a variety of different types of particle that can be synthesized using microfluidics and the exact fluidic format used defines the flow characteristics of the synthesis environment which needs to be carefully matched to the synthetic requirements of each particle type. Broadly speaking, the main particle types of interest include monodisperse microgels, metal nanoparticles and nanocrystals, core-shell particles, microemulsions, and microcapsules. Typically these particles should be homogeneous in size and are composed either of an organic polymer matrix or a metal or metal mixture at the micron or nanometer scale. In addition to these simple particle architectures, we may also consider more complex particles composed of multiple layers or components such as core-shell particles or using a central cavity to encapsulate small molecules, proteins, or other particles, and these are called microcapsules. 

Nanostructured materials obtained by sol-gel encapsulation of biomolecules are a novel class of biomaterials. The biological macromolecules, confined within the nanometer-size pores of the matrix, show both similarities to and differences from solution characteristics. The effects of nanoconfinement on the structural and reactivity patterns of the proteins and enzymes are discussed. The applications of these nanostructured biomaterials in the area of molecular biorecognition, detection, and biosensing are also presented. 

Nanostructured materials are characterized by ordered structural domains,at the level of nanometers (7). These materials display the properties of condensed matter without a long range order. In general, four types of such materials based on the integral modulation dimensionalities of zero (nanoconfined particles), one (linear tunnel or channel structures two (multilayers) and three (nanophases) are possible (2). The simplest nanostructured materials are the nanoconfined systems of zero modulation dimensionality which consist of a host matrix with a nm-size spatial cavity that can act as an enclosure for dopant molecular particles. The nanostructured materials obtained by encapsulation of biological macromolecules in sol-gel derived porous Si02 structures that contain a trapped bioparticle represent a particularly novel and recent example in this category (5-4). 

The application of Sn anodes is still hampered by their inherent poor cycling stability resulting from the large volume change. Several strategies have been proposed to overcome this problem. One of the effective strategy is to prepare intermetallic compounds (M M), which consist of an inactive phase M and an active phase M . Another useful approach is either to disperse the nanometer-sized tin-based materials into a carbon matrix or to prepare the carbon-encapsulated hollow tin nano-particles. The carbon component has good elasticity to effectively accommodate the strain of... 

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