Electrospinning: A facile method to disperse fluorescent quantum dots in nanofibers without Forster resonance energy transfer

Fluorescent CdTe quantum dots (QDs) can be dispersed into poly(vinyl alcohol) (PVA) solid nanofibers by electrospinning of a QD-PVA blend solution. Although solution blending methods usually cause phase separation as the solvent evaporates; here, attractively, the QDs do not aggregate, on the contrary, they attain a separation and distribution in the PVA matrix that is as good and uniform as that in solution. Consequently, Forster resonance energy transfer (FRET) between QDs is efficiently avoided, leading to the good preservation of the original fluorescence properties of QDs even when multi-color QDs are incorporated. Thus, the emission color of the solid nanofibers can be well predicted from the electrospinning solution. Further investigation reveals that the fast evaporation rate of the solvent in the electrospinning process lies at the basis of the uniform distribution of the QDs. Because of the quick freezing of the polymer chains, the CdTe QDs are confined to their places with no time to aggregate.