We present simultaneous measurements of both the small angle light scattering (SALS) structure factor and the dichroism for near-critical polymer solutions in electric fields. The theory of flow birefringence and dichroism proposed by Onuki and Doi is extended to the electric field case. This theory relates the electric-field-induced form dichroism to the second moment of the structure factor. Excellent agreement is observed between the form dichroism calculated from measured scattering intensities and the dichroism measured by optical polarimetry. In addition, a possible mechanism of dipolar coupling between the large critical concentration fluctuations and the electric field is proposed. Similar simultaneous SALS and birefringence measurements confirm this model of dipolar interaction.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry