Nanostructured light metal-based

Key words hydrogen storage/nanostructured light metal-based hydrides/controlled reactive mechanical alloying/magnesium hydride/amorphous hydrides... 

NANOSTRUCTURED AND NANOCOMPOSITE LIGHT METAL-BASED COMPOUNDS FOR HYDROGEN STORAGE... 

Polymeric aerogels based on RF were developed in the last years for application in foundry practice as a new nanostructured binder for foundry sands. Their properties allow, for instance, to replace conventional polymeric binders, since they solve certain problems of core removal, penetration, surface reactions, blow holes, and other casting defects especially in light metal casting. RF aerogels as polymeric binders are at the verge of being used by industry. 

Other uses of nanostructured chromophores may include fluorescent nanoparticles or nanoparticle-based porous materials that change their light absorption or emission when a toxin is encountered. Some metal oxides and POMs already exhibit such properties. Likewise, electrochemical properties, including induced photocurrents, could be sensitive to encountering a toxin. Clearly, both decontamination and detection are relevant aspects here. Basic research is needed on the design and synthesis of engineered nanostructures whose electronic structures, thermal catalytic, photophysical (emission), and photocatalytic properties are strongly perturbed by the presence or absence of toxic compounds. 

Surface-enhanced Raman spectroscopy (SERS) is based on the amplification of the Raman effect - the inelastic scattering of light at molecules - at nanostructured metal surfaces. If light is scattered at molecules, a dipole moment H is induced to the molecule by an incident electromagnetic field E as described in Eq. 1. Here, oc represents the polarizability of the molecule - a measure to what extent the electric field E is able to disturb the electron density of a molecule out of its equilibrium configuration ... 

The electromagnetic enhancement mechanism features the major contribution to the overall enhancement of SERS. It is based on the generation of an electromagnetic field at the surface of nanostructured metal surfaces due to the interaction of an incident electromagnetic field and the excitation of localized surface plasmon polaritons. To explain this phenomenon in more detail, a simple model can be used. A simple metal nanosphere with a size smaller than the wavelength of the incident light is considered for this purpose. This metal nanosphere is surrounded by a medium or vacuum with a dielectric constant Eq, and all appearing processes are assumed to be quasi-static. The dielectric constant inside the metal nanosphere is independent of the size of the sphere and is described as follows ... 

---