The synthesis of multicomponent nanoscale structures with precisely addressable function is critical to the discovery of both new phenomena and new applications in nanotechnology. Though self-assembly offers low-cost routes to many such materials, these methods often require building blocks with particular structural motifs, thus limiting the scope of nanomaterials that can be prepared in these ways. Herein we use a bottom-up approach based on covalent chemistry to synthesize a series of bottlebrush copolymers from red, green, and blue luminescent macromonomers, which were then used to prepare multiblock organic nanofibers structurally analogous to nanoscale RGB pixels. Efficient energy transfer from a blue fluorophore to red and green phosphors can be modulated, using the solvent polarity as a stimulus, to give aggregation-induced changes in emission color. Aggregation was also accompanied by changes in the emission lifetime of the nanofiber from the nanosecond to microsecond regime. Additionally, changes in energy transfer efficiency and interchromophore distance were quantified using a FRET model. Preliminary demonstration of these materials as polarity-sensitive inks for encryption and encoding were also demonstrated using a red/blue fluorescence switch upon exposure to solvent. Finally, the potential complexity of optoelectronic materials accessible with these methods was demonstrated by combining these building blocks with charge-transporting materials to give organic nanofibers with ordered structures mimicking that of multilayer white OLEDs. Ultimately this work describes the preparation of robust, multicomponent nanofibers from general building blocks, combining their optoelectronic properties in ways that can be both reversibly switched and temporally resolved.

Three acrylic monomers have been prepared based on organic semiconductor motifs commonly used as n-type materials in organic light-emitting diodes (OLEDs) and organic thin-film transistors (OTFTs) and polymerized by Cu(0)-RDRP.

Methods are described for the preparation of fiber-like nanomaterials that mimic the multilayer structure of organic electronic devices on individual polymer chains. By combining Cu(0) reversible-deactivation radical polymerization (RDRP) and ring-opening metathesis polymerization (ROMP), multiblock bottlebrush copolymers are synthesized from ordered sequences of organic semiconductors. Narrowly dispersed fibers are prepared from materials commonly used as the hole transport, electron transport, and host materials in organic electronics, with molecular weights exceeding 2 × 10 Da and dispersities as low as 1.12. Diblock nanofibers are then synthesized from pairs of semiconducting building blocks, giving nanostructures analogous to p- n junctions that exhibit the reversible electrochemistry of their individual parts. Finally, this strategy is used to construct nanofibers with the structure of phosphorescent organic light-emitting diodes (OLEDs) on single macromolecules, such that the photophysical properties of each component of an OLED can be independently observed. These multiblock nanofibers can be formed from arbitrary organic semiconductors without the need for crystallinity, selective solvation, or supramolecular interactions, providing powerful methods for the miniaturization of materials for organic devices.

A series of four acrylic monomers were synthesized based on p-type organic semiconductor motifs found commonly in organic light-emitting diodes (OLEDs), organic thin-film transistors (OTFTs) and organic photovoltaics (OPVs).