Dispersion of Dielectric Permittivity in a Nanocrystalline Cellulose-Triglycine Sulfate Composite at Low and Ultralow Frequencies

摘要

The dispersion of dielectric permittivity in nanocrystalline cellulose-triglycine sulfate composites is studied in the range of frequencies from 10(-3) to 10(6) Hz, at temperatures varying from room temperature to the temperature of phase transition in this composite (54A degrees C), in weak electric fields (1 V cm(-1)). Two behaviors for the dielectric dispersion are identified in the studied frequency range: at ultralow frequencies (10(-3)-10 Hz), the dispersion is due to Maxwell-Wagner polarization, while at higher frequencies (10-10(6) Hz), the dispersion is due to the movement of domain walls in the embedded triglycine sulfate crystallites. An additional peak in the temperature-dependent profiles of dielectric permittivity is detected at lower temperatures in freshly prepared samples of the considered composite; we associate it with the presence of residual water in these samples.