title: Encapsulation of MEH-PPV:PCBM Hybrids in the Cores of Block Copolymer Micellar Assemblies: Photoinduced Electron Transfer in a Nanoscale Donor-Acceptor System.
abstract: The objective of this work is to demonstrate that conjugated polymer:fullerene hybrid nanoparticles encapsulated in the hydrophobic cores of triblock copolymer micelles may successfully act as spatially confined donor-acceptor systems capable of facilitating photoinduced charge carrier separation. To this end, aqueous dispersions of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) nanoparticles were first prepared by solubilization of the polymer in the cores of poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) triblock copolymer, Pluronic F-127 micelles. A number of significant optical spectroscopic changes were observed on transfer of the conjugated polymer from a nonaqueous solvent to the aqueous micellar environment. These were primarily attributed to increased interchain interactions due to conjugated polymer chain collapse during encapsulation in the micellar cores. When prepared in buffer solution, the micelles exhibited good long-term collodial stability. When MEH-PPV micelles were blended by the addition of controlled amounts of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), the observed correspondence of photoluminescence emission quenching, quantum yield decreases, and emission lifetime shortening with increasing PCBM concentration indicated efficient photoinduced donor-to-acceptor charge transfer between MEH-PPV and the fullerenes in the cores of the micelles, an assignment that was confirmed by transient absorption spectroscopic monitoring of carrier photogeneration and recombination.
authors.affiliation: School of Chemistry, University College Dublin , Belfield, Dublin 4, Ireland.
authors.forename: Suxiao
authors.initials: S
authors.lastname: Wang
authors.affiliation: Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, 43007 Tarragona, Spain.
authors.forename: James William
authors.initials: JW
authors.lastname: Ryan
authors.affiliation: School of Chemistry, University College Dublin , Belfield, Dublin 4, Ireland.
authors.forename: Amita
authors.initials: A
authors.lastname: Singh
authors.affiliation: School of Chemistry, University College Dublin , Belfield, Dublin 4, Ireland.
authors.forename: Jason Gerard
authors.initials: JG
authors.lastname: Beirne
authors.affiliation: Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, 43007 Tarragona, Spain.|Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Palomares
authors.affiliation: School of Chemistry, University College Dublin , Belfield, Dublin 4, Ireland.
authors.forename: Gareth
authors.initials: G
authors.lastname: Redmond