EFFECTS OF EXTERNAL ELECTRIC-FIELD ON SEMIDILUTE POLYMER-SOLUTIONS PROBED BY DYNAMIC LIGHT-SCATTERING

Dynamic light scattering studies of polystyrene (PS) in tetrahydrofura n (THF) in 1,4-dioxane (DO) and in THF/DO mixed solvent, subject to an external de field, have been carried out. In THF the rate constant fo r the decay of the intensity autocorrelation function (IACF) is found to increase with increasing the external applied electric field; in DO , the electric field is found to have only a negligible effect on the IACF; in the mixed solvent it exhibits an intermediate effect, dependi ng on the THF content. A hydrodynamic theory is proposed to account fo r the observed electric field induced effect in THF. (C) 1997 American Institute of Physics.