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From Nowick's self-induced ordering theory, we develop a new configurational entropy relation to describe the non-Arrhenius temperature (T)-dependent relaxation in disordered systems. Both the loss of configurational entropy and the coupling interaction among relaxing units (RUs) are explicitly introduced in this relation; thus, this relation offers a novel connection, which differs from the Adam-Gibbs (A-G) entropy relation, between kinetics and thermodynamics, and this relation generalizes several well-known currently used relations. The present relation can provide direct and more accurate estimates of (i) the intrinsic activation enthalpy, (ii) the T-evolution of the configurational entropy loss of the system, and (iii) the self-induced ordering temperature Tc, which characterizes the coupling interaction among RUs. The application of the theory to experimental data for the relaxation time in typical organic liquids demonstrates the validity of the theory. [ABSTRACT FROM AUTHOR]

Experimental investigations based on our custom-built torsion resonator were carried out on the kinetics and relaxation of the structural formation process in three agar-water solutions with agar concentrations of 0.75, 1.0, and 2.0 % w/w under natural cooling. An interesting temperature-dependent oscillatory decaying behavior of the structure development rate (SDR) in the agar gelation process is observed. This oscillatory SDR-decaying behavior is indicative of a sum of multiple SDR-determining relaxation processes and could be quantitatively described by a multiple-order Gaussian-like equation, i.e., $dG^{\prime }/dt\equiv \sum \nolimits _{n=0}^{m}{dG^{\prime }/dt}^{(n)}=\sum \nolimits _{n=0}^{m}K_{n}{\rm exp}[-2(T-T_{n})^{2}/W_{n}^{2}]$. The ${\rm T}_{n}$ dependences of ${\rm W}_{n}$ in the gelation zone were also found to follow the Arrhenius law with activation energies of 39-74 kJ/mol for three investigated samples, indicating the important role of formation or fission of the hydrogen bonding interaction playing in the agar structural network formation. These findings provide insights into the mechanical properties and distinctive structure development rates of agar sols that dynamically and naturally evolve to form gels. [ABSTRACT FROM AUTHOR]