Sub-molecular dynamics in liquids and polymers

Abstract

An extension of Adam-Gibbs theory at its molecular level is proposed. New relations, measuring the number of the configurations within the cooperatively rearranging regions, are found. By these relations the transformation of activated-hopping to free-diffusion dynamics can be observed as a measurement of the number of the sub-molecular dynamic units, known in the literature as “beads”. Two new methods for measuring the number of the beads in the molecules have been found. One of the methods used the thermodynamics results, and the second one used both the thermodynamics and relaxation ones. The measured number of beads in the twelve liquids is compared with the measuring by other theories. The evolution of the liquid state by measuring the number of the configurations within the cooperatively-rearranging regions is presented. With the suggested equations, the molecular level of Adam-Gibbs theory becomes a completed theory, permitting all molecular quantities, in the theory, to be measured by experimental results.