Ton-Matrix Coupling in Polymer Electrolytes from Relaxation Time Studies. Alcohol Obtained from Them.
Final technical rept. 1 Feb-4 Aug 87
PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY
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We review the effects of temperature on conductance and viscosity in the liquid state of vitreous ionic conductors and show how differences may be best understood by comparison of relaxation times for electrical and mechanical stresses acting on liquid or glassy states of the material. This leads to the definition of a conductivityviscosity mode decoupling index, useful as a figure of merit for the solid electrolyte. In applying the same approach to polymer electrolyte systems a problem is encountered due to the molecular weight dependence of the viscosity. This is resolved by deriving a monomer shear relaxation time for the polymer electrolyte solution and showing that this quantity corresponds closely with the local mechanical relaxation time obtained from light scattering studies which is a molecular weight independent quantity for pure polymers. Comparison of the electrical relaxation times of the polymer solution with the local or matrix relaxation times then shows that the relationship found for supersonic glassforming systems is inverted in the case of polymer electrolytes.
- Physical Chemistry