Single-Molecule Imaging Revealing the Deformation-Induced Formation of a Molecular Polymer Blend

Photoluminescence microscopy of conjugated polymer molecules in a polyethylene host has been applied to monitor the transition of a phase-separated polymer blend into a molecular dispersion induced by solid-state tensile deformation. Statistical analysis of conjugated polymer cluster sizes as a function of the degree of matrix deformation shows that phase-separated domains of conjugated polymer transform into smaller clusters and single molecules as the degree of matrix deformation increases. Concomitantly, the conjugated guest molecules tend to adopt the preferential orientation of the surrounding matrix. We demonstrate that single-molecule detection can be readily extended and applied to probing molecular dispersion, orientation, and morphology in polymer−polymer blends.