Exploring dielectric properties and polarization relaxation processes in ionic liquid crystals with synthesized carbon and gold nanoparticles

Abstract

The main goal is to study the structural and dielectric characteristics of advanced composite materials based on ionic metal alkanoates with various types of nanoparticles. The matrix Cd⁺²(C₇H₁₅COO)⁻² formed as a result of the reaction of cadmium with the carboxylate groups of alkanoate (C₇H₁₅COO)⁻² is used for the synthesis of nanoparticles. At room temperature, the matrix of the ionic crystalline material represents multilayer structure with each layer thickness of 1.8 nm. However, when heated in the temperature range from 100 °C to 180 °C, the matrix undergoes a phase transition into the liquid crystalline smectic A phase, preserved after cooling to room temperature. This transition opens up possibilities for the synthesis of carbon and gold nanoparticles. The temperature treatments of the matrix allow to control of the size and shape of nanoparticles during synthesis and create highly stable nanocomposites. The structural features and dielectric properties of these nanocomposites are studied using transmission electron microscopy, enabling to determine of the sizes of nanoparticles and their dispersion and impedance spectroscopy, respectively. Dielectric properties of nanocomposite materials were studied at different temperatures corresponding to two material phases. We carried out an analysis of the dielectric characteristics of the pure matrix in comparison with nanocomposite materials, containing carbon and gold nanoparticles to identify the role of the nanoparticles. Based on our experimental data, we proposed a model to explain the charge transfer process, taking into account relaxation processes and polarization of nanocomposite materials.

Keywords:

• Dielectric properties
• liquid crystals
• nanocomposites
• nanomaterials
• nanoparticles

Acknowledgments

D. Zhulai greatly appreciates a research grant from the German National Academy of Sciences Leopoldina.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors acknowledge funding from NASU via the project [No. 0123U100832].