Nanostructured carrier material

Also, many enzymes, e.g., lipases, improve their activity upon the adsorption onto nanostructured carrier materials [106]. 

All in all, it is obvious that dextran will gain increasing importance as a carrier material in pharmaceutical applications, as a basis for bioactive derivatives and as a nanostructured device. Dextran and modified dex-trans should always be considered as a biocompatible material with a high structure-forming potential. 

To summarise these few experimental results, it can be stated that electronic transport in many nanostructured polycrystalline materials appears to be rather poor, particularly when the transport path involves grain boundaries. Yet in many cases the transport conditions can be improved by operating these films under majority-carrier transport conditions and exploiting trap filling under high-injection conditions. Efficient charge collection can then often be achieved. In absorber layers, where both carrier types are necessarily present, these conditions cannot usually be implemented. 

How can such problems be counterbalanced Since a large capacitance of a semiconductor/electrolyte junction will not negatively affect the PMC transient measurement, a large area electrode (nanostructured materials) should be selected to decrease the effective excess charge carrier concentration (excess carriers per surface area) in the interface. PMC transient measurements have been performed at a sensitized nanostructured Ti02 liquidjunction solar cell.40 With a 10-ns laser pulse excitation, only the slow decay processes can be studied. The very fast rise time cannot be resolved, but this should be the aim of picosecond studies. Such experiments are being prepared in our laboratory, but using nanostructured... 

One-dimensional (ID) nanostructures have also been the focus of extensive studies because of their unique physical properties and potential to revolutionize broad areas of nanotechnology. First, ID nanostructures represent the smallest dimension structure that can efficiently transport electrical carriers and, thus, are ideally suited for the ubiquitous task of moving and routing charges (information) in nanoscale electronics and optoelectronics. Second, ID nanostructures can also exhibit a critical device function and thus can be exploited as both the wiring and device elements in architectures for functional nanosystems.20 In this regard, two material classes, carbon nanotubes2131 and semiconductor nanowires,32"42 have shown particular promise. 

Catalysts were some of the first nanostructured materials applied in industry, and many of the most important catalysts used today are nanomaterials. These are usually dispersed on the surfaces of supports (carriers), which are often nearly inert platforms for the catalytically active structures. These structures include metal complexes as well as clusters, particles, or layers of metal, metal oxide, or metal sulfide. The solid supports usually incorporate nanopores and a large number of catalytic nanoparticles per unit volume on a high-area internal surface (typically hundreds of square meters per cubic centimeter). A benefit of the high dispersion of a catalyst is that it is used effectively, because a large part of it is at a surface and accessible to reactants. There are other potential benefits of high dispersion as well— nanostructured catalysts have properties different from those of the bulk material, possibly including unique catalytic activities and selectivities. 

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