The Physical and Spectroscopic Study of a Series of Poly(3-hexyl thiophene) Homopolymers and Poly(3-hexyl thiophene)-block-Poly(2-hydroxyethyl methacrylate) Diblock Copolymers
poly(3-hexyl thiophene) , diblock copolymer
In block-selective solvent, the rod-coil block copolymers can form various micellar structures. With block copolymers that contain a conjugated polymer block, the conformation of the conjugated polymer can be reflected by spectral changes in the solution. Therefore, it is of interest to study the relationship between the spectral changes and the nature of the conjugated polymer. The fundamental physical properties of poly(3-hexyl thiophene) (P3HT) were studied. Five P3HT samples with different molecular weights were used. We have determined the relationship between physical and spectral properties of this polymer and its molecular weight. In particular, we have found that the refractive index increments, the maximum absorbance wavelength, extinction coefficients, and the emission wavelengths, increase with molecular weight. Diblock copolymers of poly(3-hexyl thiophene)-block-poly(2-hydroxyethyl methacrylate) (P3HT-b-PHEMA) were also studied. The morphological and spectral changes of these block copolymers were studied at various stages of micelle formation in block selective solvents. The relationship between the volume fraction of the P3HT block and their physical and spectral properties were also discussed.