Broadband Dielectric Spectroscopy and Its Application in Polymeric Materials

Abstract

Relaxation processes in polymeric systems span over an extremely wide range of time scales. There are a few experimental techniques capable of covering such a range, and one of the most versatile of them is Broadband Dielectric Spectroscopy (BDS). Current BDS covers an enormous frequency range, from ∼10 −5 to ∼10 12 Hz, enabling a practical study of the full spectrum of relaxation phenomena in a broad temperature and pressure range without involvement of time‐temperature superposition. In this article, we present capabilities of the BDS technique on examples of different polymeric systems and explain what kind of information can be extracted from the frequency spectra of the dielectric permittivity and conductivity. We present examples of dielectric studies of segmental and chain dynamics, secondary relaxations, explain additional phenomena in multicomponent systems (e.g. polymer nanocomposites and block copolymers), and discuss specifically examples of ion‐conducting polymers. We emphasize that BDS does not probe molecular motions directly and measures fluctuations of dipoles or diffusion of charges. So, combination of BDS with other experimental techniques is the best approach to study dynamics of various materials.

Thermal and Dielectric Investigations of Polystyrene Nanoparticles as a Viable Platform—Toward the Next Generation of Fillers for Nanocomposites

“…Broadband dielectric spectroscopy (BDS) is a non-invasive experimental technique that characterizes the fluctuations of electric dipole moments within the molecules and the diffusion of charge carriers through a material backbone [21,22]. These measurements usually cover a vast frequency range and may be performed in a large range of temperatures, allowing investigation of molecular relaxation processes of different materials [23,24].…”

Unifying Physical Framework for Stretched-Exponential, Compressed-Exponential, and Logarithmic Relaxation Phenomena in Glassy Polymers

“…Relaxation (dielectric, − mechanical, − specific volume, − or enthalpy − ) experiments and simulations − are important tools in understanding the behavior of glassy and near-glassy polymers. ,, Unlike conventional liquids, glassy materials exhibit relaxations that substantially deviate from the standard Debye single-exponential decay. In some cases, the material property of interest changes slowly over many decades in time (“stretched relaxation”), while in others, it exhibits no change until a sudden avalanche-like event takes place (“compressed relaxation”).…”

Lithium-Ion Transport and Exchange between Phases in a Concentrated Liquid Electrolyte Containing Lithium-Ion-Conducting Inorganic Particles

“…In impedance studies, when the frequency of the applied AC potential is low, ions are blocked at the electrode/electrolyte interface and cause electrode polarization. Increasing the distance between electrodes shifts electrode polarization to even lower frequencies. − Figure b shows a lab-built cell used to measure the conductivity of the suspensions. The electrodes are separated by 2.2 cm, and the cell constant is calibrated to be 19.5 cm –1 .…”

“…Increasing the distance between electrodes shifts electrode polarization to even lower frequencies. 44 − 46 Figure 1 b shows a lab-built cell used to measure the conductivity of the suspensions. The electrodes are separated by 2.2 cm, and the cell constant is calibrated to be 19.5 cm –1 .…”