MOLECULAR CHARACTERIZATION OF POLY(3-HEXYLTHIOPHENE)

A complete molecular characterization of poly(3-hexylthiophene) (P3HT) in dilute solution was conducted by using static and dynamic light scattering, gel permeation chromatography, and viscosity measurements. The dependence of the intrinsic viscosity and the radius of gyration upon molecular weight was determined in THF for 40 000 less-than-or-equal-to M(w) less-than-or-equal-to 220 000 and found to be characteristic of a moderately good solvent. Similar solution characteristics were observed in chloroform. A comparison of the macromolecular dimensions determined by different techniques was made to demonstrate the consistency of the data, which indicate that the P3HT macromolecules exist as isolated flexible-coil chains in dilute THF solution with a persistence length of 2.4 +/- 0.3 nm.