Generic Primary Mechanical Response of Viscous Liquids

Area of Science:

• Condensed matter physics
• Rheology
• Dielectric spectroscopy

Background:

• Jonscher's seminal 1977 review highlighted a "remarkable universality" in the dielectric response of conducting materials.
• This universality suggests underlying common principles governing material properties.

Purpose of the Study:

• To connect the fields of charge transport in conducting materials and mass flow in viscous liquids.
• To demonstrate that concepts from dielectric response analysis can be applied to rheological spectra and vice versa.
• To establish a link between microscopic and macroscopic viscoelastic characteristics of liquids.

Main Methods:

• Analysis of dielectric response universality in conducting materials.
• Examination of shear rheological spectra in nonpolymeric viscous liquids.
• Application of concepts from charge transport to mass flow dynamics.

Main Results:

• The study demonstrates that shear rheological spectra of nonpolymeric viscous liquids exhibit the same universal response pattern as dielectric spectra of conducting materials.
• A virtual equivalence between charge transport dynamics and mass flow dynamics is established.
• A new relation, analogous to the Barton-Nakajima-Namikawa relation for conductivity, is proposed for viscoelastic characteristics.

Conclusions:

• Concepts developed for charge transport can be effectively employed for the description of mass flow in liquids, and conversely.
• The findings bridge two previously distinct branches of condensed matter physics.
• A unified framework for understanding viscoelastic properties based on universal response patterns is presented.