Dielectric Properties of Multi-Phase Systems

As we have seen, the highest dielectric permittivity is found in such solids which are heterogeneous on microscopic level. The effect can be even more drastic in multiphase systems, especially if one of the phases is water. In 1934 Smith-Rose [91] discovered that soils, which in dry state have s of 2-10, increase it by several orders of magnitude if impregnated with water (which has 80). Later, similar 

On the other hand, even traces of DND drastically affect the physical properties of liquid water, increasing its from 80 to over 10 and altering some other physical properties (e.g. sound velocity), this effect can be attributed to interfacial water, which is known to differ substantially in its properties from the surrounding bulk water [96-98], Similar, although much weaker effects were observed in other polar solvents. 

The role of adsorbed water on the diamond surface is now recognized as important in other respects as well. Thus, it may be responsible for the surface conductivity of diamond [95, 104]—a highly unusual property, especially as bulk diamond is the best insulator material known. 

As noted in previous chapters of this book, crystal structure parameters (coordination numbers, interatomic distances, unit cell volumes), characteristics of phase transformations, and physical properties of samples can depend on the size of crystal grains the detailed reviews of the size effect in different mechanical properties of nanomaterials can be found in [9,105]. In the present chapter it is shown that the size effect is especially significant for electrophysical properties of crystals, including the effect of dispersed powders on the properties of polar liquids contacting with them. 

Obviously, the topics discussed in this and other chapters cover only a small part of the structural chemistry of nanomaterials. Besides, this area now experiences such explosive growth that any review becomes outdated very quickly. It is worth recollecting that the first review on this subject (1978) contained 5 references, while in 2008 the number of publications available exceeded 500,000. 

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