A photoluminescence study of electrospun fibers of conjugated poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] blended with poly(9-vinylcarbazole)

Flat ribbon-like electrospun fibers of poly(9-vinylcarbazole) (PVK)/Poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with thickness ranging from 2 to 6 μm were prepared by electrospinning. The blue emission of the PVK fibers changed to greenish-yellow, with incorporation of MEH-PPV up to 13 wt% content. By analyzing the photoluminescence spectra, we found a significant blue shift of the MEH-PPV emission band in the blend fibers evidencing that PVK prevents aggregation in the MEH-PPV, suppressing the formation of interchain interactions. The morphologies of the blend fibers characterized by TEM, corroborates that multiple coalescing MEH-PPV droplets merge together as PVK content decreases. Compared with PVK/MEH-PPV spin-cast films, blend nanofibers exhibited a more efficient energy transfer due to effective interfacial interactions between PVK and MEH-PPV, at low MEH-PPV content. Our results showed that by using this electrostatic processing method, photophysical properties of light-emitting fibers prepared from polymer blends can be tuned.