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

Abstract

Aggregation and continuous π-stacking have been the major obstacles hindering the fluorescence (FL) quantum yield (<i>Φ</i> _F) of perylene diimide (PDI) derivatives in the condensed phase. To prepare polymer microspheres with nearly unity <i>Φ</i> _F, in this work a POSS functionalized PDI derivative, POSS-PDI-POSS (PPP), was applied as the red fluorophore of poly(3-hydroxylbutyrate-<i>co</i>-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 <i>Φ</i> _F of the embedded PPP fluorophore. Both the PPP/PHBV and the PPP/PS microspheres show higher <i>Φ</i> _F than most PDI materials in the condensed phase. The PPP/PHBV microspheres show <i>Φ</i> _F of 28%, whereas the PPP/PS microspheres give nearly unity <i>Φ</i> _F.