Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

The investigation of thermal and dielectric properties of carbon dots dispersed in PMMA has been conducted in freestanding thin solid films. Thermal properties were studied using differential scanning calorimetry. Impedance spectroscopy, in the frequency range 100 Hz to 100 kHz and temperatures between 200 and 390 K, was used for the electrical characterization. Using the electric modulus formalism, it has been found that the Havriliak-Negami model of dielectric relaxation is adequate to fit the experimental data, from which the relaxation parameters can be calculated. The inclusion of C-Dots in PMMA provides a plasticizing effect on the polymer structure, giving rise to an increase in the mobility of PMMA chains, and consequent changes in the relaxation parameters.