Shaping thiophene oligomers into fluorescent nanobeads forming two-dimensionally patterned assemblies by the capillary effect

We demonstrate that highly stable fluorescent nanobeads can be obtained by emulsion copolymerization of oligothiophene methyl methacrylates and styrene and that deposition on a planar surface by microfluidic lithography induces the spontaneous nanobead self-assembling. The average nanobead diameter was controlled in the submicron scale by varying the amount of surfactant used in the polymerization reaction. Photoluminescence and pump-probe experiments proved that the nanobeads had retained the optical signature of the oligothiophenes, yet preventing their aggregation. Scanning electron microscopy images of the self-assembled nanobeads are reported.