Nanostructures spectroscopic properties

In the above sections, our attention was primarily focused on the structural and optical properties of lanthanide doped in nanoparticles such as spherical QDs. Lanthanides doped in some other novel low-dimensional nanostructures including core-shell, one-dimensional (ID) nanowires and nanotubes, two-dimensional (2D) nanofilms, hollow nanospheres, 2D nanosheets and nanodisks have also attracted extensive attention. It is expected that their unique structures could result in unusual mechanical, electronic, optical and magnetic properties. So far few papers have been reported for lanthanide ions other than Eu3+ in these materials. Much attention is focused on the optical properties of Eu3+ ions in view of their very good spectroscopic properties. 

In a further step, Yam and coworkers constructed helical superstructures emplo5nng chiral alkynylplatiniun(II)-terpyridyl complexes, obtaining metallogels that show helical fibrous nanostructures. The chiral supramolecular structiue and the spectroscopic properties depend on the extent of aggregation through Pt- Pt and n-n interactions, which can be influenced by varying the nature of counteranions, as revealed by UV/vis, circular dichroism, and luminescence studies (221). 

The atomic and molecular structure of tribological surfaces and lubricants under shear plays a crucial role in tribology. Unfortunately, techniques to probe nanostructure spectroscopically or optically simultaneously with tribological probing are limited. This limits the ability to draw conclusive structure-property relations for all but the most idealized macroscopic surfaces, such as those described here. 

The development of nanostructured conductive polymers also requires the development of advanced characterisation techniques, and this aspect of current research is captured in several chapters. A detailed review of Atomic Force Microscopy (AFM) covers the wide range of related scanning probe microscopes that are particularly relevant to soft materials. It also shows how techniques such as conductive AFM go beyond structural measurements to image the functional properties of materials relevant to applications such as solar cells. A wide range of spectroscopic techniques has also been reviewed, showing how they can be applied to learn about the interactions between conductive polymers and nanostructured... 

The physical properties of QDs are ultimately the end products of a complex interplay of several fundamental processes that need to be recognised and understood before these materials may be used efficiently in devices. The optical properties of nanomaterials arise from interactions between electrons, holes, and their local environments. These properties may be affected by parameters such as size, shape, surface chemistry, dopants, the presence of other nanostructures, as well as other still undetermined characteristics of the surrounding environment. Spectroscopic probes of such optical properties thus convey a wealth of information on the behaviour and... 

Polymers organized in this unusual state behave as hexagonal mesophases similar to those observed in the bulk at suitable temperature/pressure conditions and adopt the extended chain conformation. Polymers included in nanochannels were discovered a few decades ago [33,34], but the mesomorphic properties and the stabilizing interactions were established much later by advanced spectroscopic techniques [35-41]. The preparation of novel macro-molecular adducts, melting at temperatures as high as 350 °C and sustained by CH- 71 intermolecular interactions, has been a success of supramolecular chemistry in fabricating high performance nanostructured materials [42]. 

Efforts to exploit this property for bioanalysis are being pursued by a number of companies. For example, by getting nanoparticles to attach to different molecules and emit different frequencies, it would be possible to spectroscopically determine the presence of many substances in one sample. Nanostructured materials, coupled with liquid crystals and chemical receptors, offer the cheap, portable biodetectors that might be worn as a badge. 

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