Polarization nanostructural materials

From a different point of view, wet hydrophobic ILs have been described as nanostructured materials, where cations and anions are connected together with hydrogen bonds, forming an extended network of polar and nonpolar regions [110]. In concentrated aqueous solutions of ILs, these organized structures can be maintained, and under these conditions, Hofmeister series concept could not be properly applied [82]. Moreover, enzyme molecules have been considered to be included into these IL networks, thus maintaining their native structures and the essential water molecules. In a sense, these ILs could be considered both as solvents and liquid immobilization supports in which high enzyme stability can be achieved [45, 70,90,110,111]. 

There is considerable interest in developing new types of magnetic materials, with a particular hope that ferroelectric solids and polymers can be constructed— materials having spontaneous electric polarization that can be reversed by an electric field. Such materials could lead to new low-cost memory devices for computers. The fine control of dispersed magnetic nanostructures will take the storage and tunability of magnetic media to new levels, and novel tunneling microscopy approaches allow measurement of microscopic hysteresis effects in iron nanowires. 

Size effect is another factor that strongly influences the properties of ferroelectric nanostructures, and the issue of a critical size for ferroelectricity has been actively discussed [4, 6, 11-14, 35]. For a long time it was believed that ferroelectricity was suppressed in small particles and thin films [1], and there was a critical size in order of few tens of nanometers below which a spontaneous polarization cannot be sustained in a material. Recent experimental and theoretical smdies [36 8] demonstrated that ferroelectricity exists down to vanishingly small sizes, much smaller than previously thought. These studies revealed that the issue of critical size is very complex, and electrical and mechanical boundary conditions play an essential role in nanoscale ferroelectricity. 

Faradaic processes of electrode reactions, which are principle mechanism of obtaining analytical signal in amperometric sensors, significantly depend on working electrode material and state of its surface. The common working electrode materials include noble and seminoble metals, solid oxides of various elements and different kinds of carbon materials including carbon nanostructures. They are employed in conventional voltammetric measurements with various modes of electrode polarization, as amperometric chemical sensors, as well as for construction of amperometric biosensors. 

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