The morphologies and fluorescence quantum yields of perylene diimide dye-doped PS and PHVB microspheres.

Aggregation and continuous π-stacking have been the major obstacles hindering the fluorescence (FL) quantum yield ( Φ F ) of perylene diimide (PDI) derivatives in the condensed phase. To prepare polymer microspheres with nearly unity Φ F , in this work a POSS functionalized PDI derivative, POSS-PDI-POSS (PPP), was applied as the red fluorophore of poly(3-hydroxylbutyrate- co -3-hydroxyvalerate) (PHBV) and polystyrene (PS) microspheres. The electrosprayed PPP/PHBV and PPP/PS microspheres have unique hollow structures. Moreover, they show bright red FL under a fluorescence microscope. A photophysical study of the microspheres indicates a significant role of the polymer matrix in disrupting the aggregation state and the Φ F of the embedded PPP fluorophore. Both the PPP/PHBV and the PPP/PS microspheres show higher Φ F than most PDI materials in the condensed phase. The PPP/PHBV microspheres show Φ F of 28%, whereas the PPP/PS microspheres give nearly unity Φ F .