We report the preparation and characterization of two comb-like graft copolymers, polythiophene-graft-poly(N,N-dimethylaminoethyl methacrylates) (PT700-g-PDMA60 and PT220-g-PDMA16, where the subscripts represent the number average degree of polymerization), and an investigation of their interaction with CdSe nanorods. Each polymer contains a regiorandom polythiophene (PT) as the backbone, from which poly(N,N-dimethylaminoethyl methacrylate) (PDMA) chains are densely grafted. The PDMA arms serve as multidentate ligands for CdSe semiconductor nanocrystals and increase the compatibility between the PT backbone and the nanocrystals. Using electron microscopy, we examined the morphology and the internal structure of the nanorod/polymer composites formed in toluene. The morphology and the internal structure of the composites vary with a change in the nanorod/polymer ratio as well as with the concentration of each component. The results of steady-state fluorescence spectroscopy indicate that the presence of the nanocrystals in toluene leads to photoluminescence (PL) quenching of the PT backbone in the graft copolymer with relatively short PDMA arms (PT220-g-PDMA16). In contrast, no PL quenching could be detected in composites formed from a similar polymer with longer PDMA arms (PT700-g-PDMA60). A likely explanation of this result is that in composites formed with PT700-g-PDMA60, the nanocrystals are held too far from the PT backbone for energy transfer or charge transfer to take place.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry