Electric Field Coupling to Slow Elastic Modes in Gels of Conjugated Polymers

Abstract

The interaction of low-frequency ac electric fields with the anisotropic polarizability of rodlike polydiacetylene macromolecules is used to excite slow (<50 cm/sec) transverse elastic modes in gels made up of a network of these molecules. The specific coupling of the ac field excitation and the birefringence detection to the network allows direct measurements of the fraction of the sample for which there is an elastic restoring force (the "infinite cluster").