IMF2017

In recent years, a number studies of nanoporous matrix composites with ferroelectric inclusions have been carried out. These composites satisfy high demands of modern technique and technologies due to large variations of properties by changing the material characteristics and geometry of the coupling of their components. The search for new nanoporous matrices for ferroelectric composites is going on together with attempts to improve the properties of existing nanostructured systems. Nanocrystalline cellulose is a promising material for creating matrix nanocomposite due to the presence of a large number of nanofibers and OH-groups on their surface, which determine the high sorption capacity of cellulose in relation to water-soluble compounds. Dielectric relaxation of nanocomposites prepared by using ferroelectric particles of triglycine sulfate and sodium nitrite embedded into the matrix of nanocrystalline cellulose in a large frequency range of 10^-3 to 10⁶ Hz in a weak measuring field ̴ 1 V/cm at different temperatures were investigated. The study of dielectric relaxation in the nanocomposite with triglycine sulfate showed the presence of two relaxation sections. The Debye-like relaxation is observed at higher frequencies, and the linear dispersion – at lower frequencies due to respectively the reversible and irreversible domain-wall motion of the TGS crystallites embedded into the matrix. The displacement of relaxation frequency of TGS nanoparticles to the range of lower frequencies in comparison with those of TGS single crystals was also detected. In the case of sodium nitrite, a significant dielectric dispersion caused by the interfacial polarization according to Maxwell-Wagner-Sillars mechanism was found.