Solvent vapor annealing (SVA) is an industrially important technique used to prepare polymer films that have morphology suitable for use in devices. The real-time observation (see movies below) of morphological dynamics induced by SVA in a model system has now been shown thanks to the efforts of a team at The University of Texas, Austin, USA.
In their study, a conjugated polymer (MEH-PPV) embedded in polymethylmethacrylat (PMMA) was observed on a single chain level by using single-molecule spectroscopy (SMS). The researchers investigated the translocation dynamics of single MEH-PPV chains and found clear differences on translational diffusion of single polymer chains before and during SVA, change of quantum yield of fluorescence during SVA, as well as fluorescence anisotropy (see figure). In addition, different solvents were compared when used for spin-casting or for SVA.
Overall, the ability to follow annealing effects on a single molecule level will no doubt be applied in gaining better fundamental mechanistic understanding of polymer reorganization.
Image: (c) Wiley-VCH
► Movie 1
► Movie 2
- Watching the Annealing Process One Polymer Chain at a Time
J. Vogelsang, J. Brazard, T. Adachi, J. C. Bolinger, P. F. Barbara,
Angew. Chem. Int. Ed. 2011.
- J. Vogelsang, J. Brazard, T. Adachi, J. C. Bolinger, P. F. Barbara,
Angew. Chem. 2011.