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

Abstract

The dispersion of dielectric permittivity in nanocrystalline cellulose–triglycine sulfate composites is studied in the range of frequencies from 10–3 to 106 Hz, at temperatures varying from room temperature to the temperature of phase transition in this composite (54°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 (10–106 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.