51
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Thomsson D, Sforazzini G, Anderson HL, Scheblykin IG. Excitation polarization provides structural resolution of individual non-blinking nano-objects. NANOSCALE 2013; 5:3070-3077. [PMID: 23463192 DOI: 10.1039/c3nr33513e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We propose to combine the method of fluorescence intensity centroid localization with rotation of the plane of excitation polarization. Polarized light interacts selectively with differently oriented fluorophores; thus yielding topological information on the nanometer scale, without any need for fluorophore blinking. The method is applicable to photostable individual systems, when most of the traditional super-resolution methods fail. A theoretical study is supported by experiments on 30 nm long cyclodextrin-encapsulated single polyrotaxane conjugated polymer chains.
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Affiliation(s)
- Daniel Thomsson
- Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden
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52
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Camacho R, Thomsson D, Sforazzini G, Anderson HL, Scheblykin IG. Inhomogeneous Quenching as a Limit of the Correlation Between Fluorescence Polarization and Conformation of Single Molecules. J Phys Chem Lett 2013; 4:1053-1058. [PMID: 26291377 DOI: 10.1021/jz400142x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The photophysical properties of conjugated polymers (CPs) largely depend on the interactions between the CP and its environment. We present a study of two polymers with identical conjugated backbones, bare and insulated, that showed different fluorescence excitation modulation depth histograms. However, the polarization differences are not related to differences in conformation, as commonly believed, but to the existence of "dark" chromophores in the bare polymer that are statically quenched. This results in inhomogeneous quenching of the polymer chain that breaks the correlation between excitation fluorescence polarization and conjugated polymer chain conformation.
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Affiliation(s)
- Rafael Camacho
- †Chemical Physics, Lund University, Box 124 22100, Lund, Sweden
| | - Daniel Thomsson
- †Chemical Physics, Lund University, Box 124 22100, Lund, Sweden
| | - Giuseppe Sforazzini
- ‡Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Harry L Anderson
- ‡Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, United Kingdom
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53
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Dong BX, Honmou Y, Komiyama H, Furumaki S, Iyoda T, Vacha M. Conjugated Polymer Chains Confined in Vertical Nanocylinders of a Block-Copolymer Film: Preparation, Characterization, and Optoelectronic Function. Macromol Rapid Commun 2013; 34:492-7. [DOI: 10.1002/marc.201200766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Indexed: 11/06/2022]
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54
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Hu Z, Liu J, Simón-Bower L, Zhai L, Gesquiere AJ. Influence of Backbone Rigidness on Single Chain Conformation of Thiophene-Based Conjugated Polymers. J Phys Chem B 2013; 117:4461-7. [DOI: 10.1021/jp308497k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhongjian Hu
- NanoScience
Technology Center, Department
of Chemistry and CREOL, The College of Optics and Photonics,
12424 Research Parkway Suite 400, University of Central Florida, Orlando, Florida 32826, United States
| | - Jianhua Liu
- NanoScience
Technology Center, Department
of Chemistry and CREOL, The College of Optics and Photonics,
12424 Research Parkway Suite 400, University of Central Florida, Orlando, Florida 32826, United States
| | - Lauren Simón-Bower
- NanoScience
Technology Center, Department
of Chemistry and CREOL, The College of Optics and Photonics,
12424 Research Parkway Suite 400, University of Central Florida, Orlando, Florida 32826, United States
| | - Lei Zhai
- NanoScience
Technology Center, Department
of Chemistry and CREOL, The College of Optics and Photonics,
12424 Research Parkway Suite 400, University of Central Florida, Orlando, Florida 32826, United States
| | - Andre J. Gesquiere
- NanoScience
Technology Center, Department
of Chemistry and CREOL, The College of Optics and Photonics,
12424 Research Parkway Suite 400, University of Central Florida, Orlando, Florida 32826, United States
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55
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Stangl T, Bange S, Schmitz D, Würsch D, Höger S, Vogelsang J, Lupton JM. Temporal Switching of Homo-FRET Pathways in Single-Chromophore Dimer Models of π-Conjugated Polymers. J Am Chem Soc 2012; 135:78-81. [DOI: 10.1021/ja3108643] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas Stangl
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Sebastian Bange
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Daniela Schmitz
- Kekulé-Institut für
Organische Chemie und Biochemie der Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany
| | - Dominik Würsch
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Sigurd Höger
- Kekulé-Institut für
Organische Chemie und Biochemie der Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany
| | - Jan Vogelsang
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - John M. Lupton
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
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56
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Bolinger JC, Traub MC, Brazard J, Adachi T, Barbara PF, Vanden Bout DA. Conformation and energy transfer in single conjugated polymers. Acc Chem Res 2012; 45:1992-2001. [PMID: 22775295 DOI: 10.1021/ar300012k] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In contrast to the detailed understanding of inorganic materials, researchers lack a comprehensive view of how the properties of bulk organic materials arise from their individual components. For conjugated polymers to eventually serve as low cost semiconductor layers in electronic devices, researchers need to better understand their functionality. For organics, traditional materials science measurements tend to destroy the species of interest, especially at low concentrations. However, fluorescence continues to be a remarkably flexible, relatively noninvasive tool for probing the properties of individual molecules and allows researchers to carry out a broad range of experiments based on a relatively simple concept. In addition, the sensitivity of single-molecule spectroscopy allows researchers to see the properties of an individual component that would be masked in the bulk phase. In this Account, we examine several photophysical properties of different conjugated polymers using single-molecule spectroscopy. In these experiments, we probed the relationship between the conformation of single conjugated polymer chains and the distance scale and efficiency of energy transfer within the polymer. Recent studies used polarization anisotropy measurements on single polymer chains to study chain folding following spin-casting from solution. This Account summarizes the effects of monomer regioregularity and backbone rigidity, by comparing a regiorandom phenylene vinylene (MEH-PPV) with both a regiorandom and regioregular thiophene (P3HT). Synthesis of novel polymers allowed us to explore the role of different conformation-directing inclusions in a PPV backbone. We showed that these inclusions control the conformation of individual chains and that molecular dynamics can predict these structural effects. In situ solvent vapor annealing studies explored the dynamics of polymer chains as well as the effect of solvent evaporation on the structural equilibrium of the polymer. We observed that a slower rate of solvent evaporation results in a narrow population of highly ordered polymer chains. These highly ordered single chains serve as a model system to probe the effect of conformation on energy transfer following excitation in single MEH-PPV polymer chains in two distinct experiments. In the first, we correlated the anisotropy of the fluorescence emission of individual chains with the anisotropy of their fluorescence excitation. Using this data, we derived a model for energy transfer in a conjugated polymer, simulating chromophores along a chain, coupled via Förster energy transfer. In the second experiment, super-resolution measurements demonstrated the ability of single-molecule spectroscopy to directly visualize energy transfer along a polymer chain embedded in a model device environment. A capacitive device allowed for controlled localization of hole polarons onto the polymer chain. These positive charges subsequently quenched local excitations, providing insight into the range of energy transfer in these single polymer molecules. As researchers continue to characterize conjugated polymer films and develop methods for creating multichain systems, single-molecule techniques will provide a greater understanding of how polymer morphology influences interchain interactions and will lead to a richer description of the electronic properties of bulk conjugated polymer films.
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57
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Camacho R, Thomsson D, Yadav D, Scheblykin I. Quantitative characterization of light-harvesting efficiency in single molecules and nanoparticles by 2D polarization microscopy: Experimental and theoretical challenges. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2012.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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58
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Adachi T, Lakhwani G, Traub MC, Ono RJ, Bielawski CW, Barbara PF, Vanden Bout DA. Conformational Effect on Energy Transfer in Single Polythiophene Chains. J Phys Chem B 2012; 116:9866-72. [DOI: 10.1021/jp306674t] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takuji Adachi
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Girish Lakhwani
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Matthew C. Traub
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Robert J. Ono
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Christopher W. Bielawski
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Paul F. Barbara
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - David A. Vanden Bout
- Center for Nano and Molecular Science and Technology,
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
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59
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Tachikawa T, Majima T. Single-molecule, single-particle approaches for exploring the structure and kinetics of nanocatalysts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:8933-8943. [PMID: 22324887 DOI: 10.1021/la300177h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this Article, we focus on the in situ observation of photochemical reactions on individual nanoobjects of solid catalysts using single-molecule, single-particle fluorescence spectroscopy. The use of high-resolution imaging techniques with suitable fluorogenic probes enables us to determine the location of the catalytically active sites that are related to the structural heterogeneities on the surface of the solid catalyst and the temporal fluctuation of photochemical reactivity. Furthermore, we present the real-time observation of metastable gold nanoclusters in polymer matrices at the single-cluster level. This Article encourages readers to explore the nanoworld in terms of practical applications in many fields such as fundamental physics and chemistry.
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Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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60
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Zhu X, Traub MC, Vanden Bout DA, Plunkett KN. Well-Defined Alternating Copolymers of Oligo(phenylenevinylene)s and Flexible Chains. Macromolecules 2012. [DOI: 10.1021/ma300430e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xinju Zhu
- Department
of Chemistry and
Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Matthew C. Traub
- Department of Chemistry and
Biochemistry and the Center for Nano and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712,
United States
| | - David A. Vanden Bout
- Department of Chemistry and
Biochemistry and the Center for Nano and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712,
United States
| | - Kyle N. Plunkett
- Department
of Chemistry and
Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, United States
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61
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Vogelsang J, Lupton JM. Solvent Vapor Annealing of Single Conjugated Polymer Chains: Building Organic Optoelectronic Materials from the Bottom Up. J Phys Chem Lett 2012; 3:1503-1513. [PMID: 26285629 DOI: 10.1021/jz300294m] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optoelectronic devices based on organic materials show a strong relationship between the morphological structure of the material and the function of the device. One of the grand challenges in improving the efficiencies of these devices is hence achieving morphological control throughout the entire course of processing. One of the most important postprocessing methods is solvent vapor annealing, which has repeatedly demonstrated its utility in improving the efficiency of organic-material-based devices by changing bulk-film morphology. This Perspective discusses the recent impact of single-molecule spectroscopy techniques in unraveling morphological changes and molecular dynamics and presents solvent vapor annealing as a tool to build organic optoelectronic materials from the bottom up. In particular, we discuss examples of how solvent vapor annealing at the single-chain level can be split into two different regimes, (i) the solvation regime, in which intrachain interactions and molecular dynamics during solvent vapor annealing can be probed, and (ii) the aggregation regime, in which the influence of interchain interactions can be probed. Finally, it will be shown that solvent vapor annealing in the aggregation regime can be used to build highly ordered mesoscopic objects with distinct properties such as long-range energy transfer.
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Affiliation(s)
- Jan Vogelsang
- §Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - John M Lupton
- §Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
- †Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
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62
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Iwan A, Guimarães JR, Santos MCD, Schab-Balcerzak E, Krompiec M, Palewicz M, Sikora A. Polyazomethine with vinylene and phenantridine moieties in the main chain: Synthesis, characterization, opto(electrical) properties and theoretical calculations. HIGH PERFORM POLYM 2012. [DOI: 10.1177/0954008312440470] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The opto(electrical) properties and theoretical calculations of polyazomethine with vinylene and phenantridine moieties in the main chain were investigated in the present study. 2,5-Bis(hexyloxy)-1,4-bis[(2,5-bis(hexyloxy)-4-formyl-phenylenevinylene]benzene was polymerized in solution with 3,8-diamino-6-phenylphenanthridine (PAZ-PV-Ph). The temperatures of 5% weight loss ( T5%) of the polyazomethine was observed at 356 °C in nitrogen. Electrochemical properties of thin film of the polymer were studied by differential pulse voltammetry. The HOMO level of the PAZ-PV-Ph was at −4.97 eV. The energy band gap ( Eg) was detected of approximately ∼1.9 eV. Energy band gap ( Egopt) was additionally calculated from absorption spectrum and absorption coefficient α. The absorption UV-vis spectra of polyazomethine recorded in solution showed a blue shift in comparison with the solid state. HOMO-LUMO levels and Eg were additionally calculated theoretically by density functional theory and molecular simulations of PAZ-PV-Ph are presented. Current density–voltage ( J– U) measurements were performed on ITO/PAZ-PV-Ph/Al, ITO/TiO2/PAZ-PV-Ph/Al and ITO/PEDOT/PAZ-PV-Ph:TiO2/Al devices in the dark and during irradiation with light (under illumination of 1000 W m−2). The polymer was tested using AFM technique and roughness ( Ra, Rms) along with skew and kurtosis are presented.
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Affiliation(s)
- Agnieszka Iwan
- Electrotechnical Institute, Division of Electrotechnology and Materials Science, Wroclaw, Poland
| | | | | | | | - Michal Krompiec
- Institute of Chemistry, University of Silesia, Katowice, Poland
| | - Marcin Palewicz
- Electrotechnical Institute, Division of Electrotechnology and Materials Science, Wroclaw, Poland
| | - Andrzej Sikora
- Electrotechnical Institute, Division of Electrotechnology and Materials Science, Wroclaw, Poland
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63
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Liu S, Schmitz D, Jester SS, Borys NJ, Höger S, Lupton JM. Coherent and Incoherent Interactions between Cofacial Π-Conjugated Oligomer Dimers in Macrocycle Templates. J Phys Chem B 2012; 117:4197-203. [DOI: 10.1021/jp301903u] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Su Liu
- Department of Physics & Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
| | - Daniela Schmitz
- Kekulé-Institut für
Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - Stefan-S. Jester
- Kekulé-Institut für
Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - Nicholas J. Borys
- Department of Physics & Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
| | - Sigurd Höger
- Kekulé-Institut für
Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - John M. Lupton
- Department of Physics & Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, 93053 Regensburg, Germany
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64
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Siebert R, Winter A, Schmitt M, Popp J, Schubert US, Dietzek B. Light-Induced Dynamics in Conjugated Bis(terpyridine) Ligands - A Case Study Toward Photoactive Coordination Polymers. Macromol Rapid Commun 2012; 33:481-97. [DOI: 10.1002/marc.201100753] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 01/02/2012] [Indexed: 12/25/2022]
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65
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Kobayashi H, Onda S, Furumaki S, Habuchi S, Vacha M. A single-molecule approach to conformation and photophysics of conjugated polymers. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2011.11.064] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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66
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Traub MC, Vogelsang J, Plunkett KN, Nuckolls C, Barbara PF, Vanden Bout DA. Unmasking bulk exciton traps and interchain electronic interactions with single conjugated polymer aggregates. ACS NANO 2012; 6:523-529. [PMID: 22208575 DOI: 10.1021/nn203860u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
For conjugated polymer materials, there is currently a major gap in understanding between the fundamental properties observed in single molecule measurements and the bulk electronic properties extracted from measurements of highly heterogeneous thin films. New materials and methodologies are needed to follow the evolution from single chain to bulk film properties as multiple chains begin to interact. In this work, we used a controlled solvent vapor annealing process to assemble single chains of phenylene-vinylene conjugated polymers into aggregates that can be individually spectroscopically interrogated. This approach allowed us to probe the effects of interchain coupling in isolated conjugated polymer nanodomains of controlled size. By assembling these aggregates from building blocks of both pristine MEH-PPV and MEH-PPV derivatives containing structure-directing ortho- or para-terphenyl inclusions, we were able to control the ordering of these nanodomains as measured by single aggregate polarization anisotropy measurments. Depending on the individual chain constituents, these aggregates varied from highly anisotropic to nearly isotropic, respectively facilitating or inhibiting interchain coupling. From the single chain fluorescence lifetimes, we demonstrated that these structure directing inclusions effectively break the phenylene-vinylene conjugation, allowing us to differentiate interchain electronic effects from those due to hyper-extended conjugation. We observed well-defined bathochromic shifts in the fluorescence spectra of the aggregates containing extensive interchain interactions, indicating that low-energy exciton traps in MEH-PPV are the result of coupling interactions between neighboring chain segments. These results demonstrate the power of the synthetic inclusion approach to control properties at not just the single chain level, but as a comprehensive approach toward ground-up design of bulk electronic properties.
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Affiliation(s)
- Matthew C Traub
- Department of Chemistry and Biochemistry and the Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, USA
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67
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Bange S, Scherf U, Lupton JM. Absence of Singlet Fission and Carrier Multiplication in a Model Conjugated Polymer: Tracking the Triplet Population through Phosphorescence. J Am Chem Soc 2012; 134:1946-9. [DOI: 10.1021/ja2102289] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sebastian Bange
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Ullrich Scherf
- Macromolecular Chemistry
Group,
Chemistry Department and IfP, Bergische Universität Wuppertal, Gauss-Str. 20, 42097 Wuppertal, Germany
| | - John M. Lupton
- Department
of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, United
States
- Institut für Experimentelle
und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
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68
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Electrically driven photon antibunching from a single molecule at room temperature. Nat Commun 2012; 3:628. [PMID: 22252552 DOI: 10.1038/ncomms1637] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 12/07/2011] [Indexed: 11/08/2022] Open
Abstract
Single-photon emitters have been considered for applications in quantum information processing, quantum cryptography and metrology. For the sake of integration and to provide an electron photon interface, it is of great interest to stimulate single-photon emission by electrical excitation as demonstrated for quantum dots. Because of low exciton binding energies, it has so far not been possible to detect sub-Poissonian photon statistics of electrically driven quantum dots at room temperature. However, organic molecules possess exciton binding energies on the order of 1eV, thereby facilitating the development of an electrically driven single-photon source at room temperature in a solid-state matrix. Here we demonstrate electroluminescence of single, electrically driven molecules at room temperature. By careful choice of the molecular emitter, as well as fabrication of a specially designed organic light-emitting diode structure, we were able to achieve stable single-molecule emission and detect sub-Poissonian photon statistics.
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69
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Kobayashi H, Tsuchiya K, Ogino K, Vacha M. Spectral multitude and spectral dynamics reflect changing conjugation length in single molecules of oligophenylenevinylenes. Phys Chem Chem Phys 2012; 14:10114-8. [DOI: 10.1039/c2cp41509g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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70
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Siebert R, Tian Y, Camacho R, Winter A, Wild A, Krieg A, Schubert US, Popp J, Scheblykin IG, Dietzek B. Fluorescence quenching in Zn2+-bis-terpyridine coordination polymers: a single molecule study. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm31237a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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71
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Lupton JM. Chromophores in Conjugated Polymers-All Straight? Chemphyschem 2011; 13:901-7. [DOI: 10.1002/cphc.201100770] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Indexed: 11/10/2022]
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72
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Lee JT, Chae DH, Ou Z, Kadish KM, Yao Z, Sessler JL. Unconventional Kondo effect in redox active single organic macrocyclic transistors. J Am Chem Soc 2011; 133:19547-52. [PMID: 22032465 PMCID: PMC3227745 DOI: 10.1021/ja208799q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclo[6]- and cyclo[8]pyrrole, two aromatic expanded porphyrins, were studied in a single-molecule transistor (SMT) setup. The analyses of these compounds allowed us to observe an uncommon absence of an even-odd effect in the Kondo resonance in discrete, metal-free organic macrocyclic compounds. The findings from the SMT measurements of these cyclopyrroles were in accord with those from cyclic voltammetry (CV) studies and theoretical analyses. These findings provide support for the notion that SMT measurements could be useful as a tool for the characterization of similar types of aromatic macrocyclic compounds.
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Affiliation(s)
- Jeong Tae Lee
- Department of Chemistry and Institute for Applied Chemistry, Hallym University, Chuncheon, Gangwon-do 200-702, Korea
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73
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Yamagata H, Spano FC. Vibronic coupling in quantum wires: applications to polydiacetylene. J Chem Phys 2011; 135:054906. [PMID: 21823731 DOI: 10.1063/1.3617432] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A theory describing vibronic coupling in direct band gap, one-dimensional semiconductors is developed to account for the photophysical properties of isolated, defect-free conjugated polymers. A Holstein-like Hamiltonian represented in a multi-particle basis set is used to evaluate absorption and emission due to Wannier-Mott excitons. The photophysical properties of such quantum wires are shown to strongly resemble those of Frenkel exciton J-aggregates. The 1(1)B(u) exciton coherence length and effective mass are readily determined from the ratio of the 0-0 and 0-1 line strengths, I(0 - 0)/I(0 - 1), in the photoluminescence spectrum. I(0 - 0)/I(0 - 1) is shown to follow a T(-1/2) dependence, in an excellent agreement with experiments on the red-phase of polydiacteylene.
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Affiliation(s)
- H Yamagata
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
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74
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Hu Z, Gesquiere AJ. Charge Trapping and Storage by Composite P3HT/PC60BM Nanoparticles Investigated by Fluorescence-Voltage/Single Particle Spectroscopy. J Am Chem Soc 2011; 133:20850-6. [DOI: 10.1021/ja207244z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Zhongjian Hu
- NanoScience Technology Center, Department of Chemistry and CREOL, The College of Optics and Photonics, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, Florida 32826, United States
| | - Andre J. Gesquiere
- NanoScience Technology Center, Department of Chemistry and CREOL, The College of Optics and Photonics, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, Florida 32826, United States
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75
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Habuchi S, Fujita H, Michinobu T, Vacha M. Twist Angle Plays an Important Role in Photophysical Properties of a Donor–Acceptor-Type Conjugated Polymer: A Combined Ensemble and Single-Molecule Study. J Phys Chem B 2011; 115:14404-15. [DOI: 10.1021/jp209405k] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Satoshi Habuchi
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Hiroyuki Fujita
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Tsuyoshi Michinobu
- Global Edge Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Martin Vacha
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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76
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Vogelsang J, Adachi T, Brazard J, Vanden Bout DA, Barbara PF. Self-assembly of highly ordered conjugated polymer aggregates with long-range energy transfer. NATURE MATERIALS 2011; 10:942-946. [PMID: 21983890 DOI: 10.1038/nmat3127] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/26/2011] [Indexed: 05/31/2023]
Abstract
Applications of conjugated polymers (CP) in organic electronic devices such as light-emitting diodes and solar cells depend critically on the nature of electronic energy transport in these materials. Single-molecule spectroscopy has revealed their fundamental properties with molecular detail, and recent reports suggest that energy transport in single CP chains can extend over extraordinarily long distances of up to 75 nm. An important question arises as to whether these characteristics are sustained when CP chains agglomerate into a neat solid. Here, we demonstrate that the electronic energy transport in aggregates composed of tens of polymer chains takes place on a similar distance scale as that in single chains. A recently developed molecular-level understanding of solvent vapour annealing has allowed us to develop a technique to control the CP agglomeration process. Aggregates with volumes of at least 45,000 nm(3) (molecular weight ≈ 21 MDa) maintain a highly ordered morphology and show pronounced fluorescence blinking behaviour, indicative of substantially long-range energy transport. Our findings provide a new lens through which the ordering of single CP chains and the evolution of their morphological and optoelectronic properties can be observed, which will ultimately enable the rational design of improved CP-based devices.
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77
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Blum C, Schleifenbaum F, Stopel M, Peter S, Sackrow M, Subramaniam V, Meixner AJ. Room temperature excitation spectroscopy of single quantum dots. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2011; 2:516-24. [PMID: 22003458 PMCID: PMC3190622 DOI: 10.3762/bjnano.2.56] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 06/09/2011] [Indexed: 05/23/2023]
Abstract
We report a single molecule detection scheme to investigate excitation spectra of single emitters at room temperature. We demonstrate the potential of single emitter photoluminescence excitation spectroscopy by recording excitation spectra of single CdSe nanocrystals over a wide spectral range of 100 nm. The spectra exhibit emission intermittency, characteristic of single emitters. We observe large variations in the spectra close to the band edge, which represent the individual heterogeneity of the observed quantum dots. We also find specific excitation wavelengths for which the single quantum dots analyzed show an increased propensity for a transition to a long-lived dark state. We expect that the additional capability of recording excitation spectra at room temperature from single emitters will enable insights into the photophysics of emitters that so far have remained inaccessible.
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Affiliation(s)
- Christian Blum
- Nanobiophysics Group and MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | - Frank Schleifenbaum
- Center for Plant Molecular Biology, Biophysical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Martijn Stopel
- Nanobiophysics Group and MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | - Sébastien Peter
- Center for Plant Molecular Biology, Biophysical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Marcus Sackrow
- Institut für Physikalische und Theoretische Chemie, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany
- present address: Picoquant GmbH, Rudower Chaussee 29, 12489 Berlin, Germany
| | - Vinod Subramaniam
- Nanobiophysics Group and MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | - Alfred J Meixner
- Institut für Physikalische und Theoretische Chemie, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany
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78
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Vasdekis AE, Laporte GP. Enhancing single molecule imaging in optofluidics and microfluidics. Int J Mol Sci 2011; 12:5135-56. [PMID: 21954349 PMCID: PMC3179156 DOI: 10.3390/ijms12085135] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 05/23/2011] [Accepted: 07/25/2011] [Indexed: 12/25/2022] Open
Abstract
Microfluidics and optofluidics have revolutionized high-throughput analysis and chemical synthesis over the past decade. Single molecule imaging has witnessed similar growth, due to its capacity to reveal heterogeneities at high spatial and temporal resolutions. However, both resolution types are dependent on the signal to noise ratio (SNR) of the image. In this paper, we review how the SNR can be enhanced in optofluidics and microfluidics. Starting with optofluidics, we outline integrated photonic structures that increase the signal emitted by single chromophores and minimize the excitation volume. Turning then to microfluidics, we review the compatible functionalization strategies that reduce noise stemming from non-specific interactions and architectures that minimize bleaching and blinking.
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Affiliation(s)
- Andreas E. Vasdekis
- Optics Laboratory, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland; E-Mail:
| | - Gregoire P.J. Laporte
- Optics Laboratory, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland; E-Mail:
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79
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Traub MC, Lakhwani G, Bolinger JC, Bout DV, Barbara PF. Electronic Energy Transfer in Highly Aligned MEH-PPV Single Chains. J Phys Chem B 2011; 115:9941-7. [DOI: 10.1021/jp204591p] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew C. Traub
- Center for Nano and Molecular Science and Technology and §Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Girish Lakhwani
- Center for Nano and Molecular Science and Technology and §Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Joshua C. Bolinger
- Center for Nano and Molecular Science and Technology and §Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - David Vanden Bout
- Center for Nano and Molecular Science and Technology and §Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
| | - Paul F. Barbara
- Center for Nano and Molecular Science and Technology and §Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, United States
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80
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Feist FA, Zickler MF, Basché T. Origin of the Red Sites and Energy Transfer Rates in Single MEH-PPV Chains at Low Temperature. Chemphyschem 2011; 12:1499-508. [DOI: 10.1002/cphc.201001010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Indexed: 11/10/2022]
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81
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Vogelsang J, Brazard J, Adachi T, Bolinger JC, Barbara PF. Watching the annealing process one polymer chain at a time. Angew Chem Int Ed Engl 2011; 50:2257-61. [PMID: 21351331 DOI: 10.1002/anie.201007084] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Indexed: 11/10/2022]
Affiliation(s)
- Jan Vogelsang
- Center for Nano and Molecular Science and Technology and Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712, USA.
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82
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Vogelsang J, Brazard J, Adachi T, Bolinger JC, Barbara PF. Watching the Annealing Process One Polymer Chain at a Time. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201007084] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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83
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Krasselt C, Schuster J, von Borczyskowski C. Photoinduced hole trapping in single semiconductor quantum dots at specific sites at silicon oxide interfaces. Phys Chem Chem Phys 2011; 13:17084-92. [DOI: 10.1039/c1cp22040c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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84
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Habuchi S, Oba T, Vacha M. Multi-beam single-molecule defocused fluorescence imaging reveals local anisotropic nature of polymer thin films. Phys Chem Chem Phys 2011; 13:7001-7. [DOI: 10.1039/c0cp02825h] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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85
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Flier BMI, Baier M, Huber J, Müllen K, Mecking S, Zumbusch A, Wöll D. Single molecule fluorescence microscopy investigations on heterogeneity of translational diffusion in thin polymer films. Phys Chem Chem Phys 2010; 13:1770-5. [PMID: 21152591 DOI: 10.1039/c0cp01801e] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Translational diffusion of single perylene diimide molecules in 25 nm thin polymer films was investigated by single molecule widefield fluorescence microscopy. Spatial heterogeneities in single molecule motion were detected and analyzed by a new, quantitative method which draws a comparison of log-Gaussian fits of experimentally determined diffusion coefficient-distributions and diffusion coefficient-distributions from Monte Carlo random walk simulations. Heterogeneities could be observed close to the glass transition temperature, but disappear at ca. 1.1 × T(g). At higher temperatures, heterogeneities do not exist or they average out on the time and length scales of observation. The observed heterogeneities also explain why the dependency of diffusion coefficients on temperature does not follow Vogel-Fulcher-Tammann behavior.
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Affiliation(s)
- Bente M I Flier
- Fachbereich Chemie, Universität Konstanz, Universitätsstrasse 10, 78464 Konstanz, Germany
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86
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Becker K, Gaefke G, Rolffs J, Höger S, Lupton JM. Quantitative mass determination of conjugated polymers for single molecule conformation analysis: enhancing rigidity with macrocycles. Chem Commun (Camb) 2010; 46:4686-8. [PMID: 20526491 DOI: 10.1039/c0cc00670j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combination of advanced synthetic and single molecule spectroscopic techniques allowed us to demonstrate that macrocycles, covalently bound to a conjugated polymer backbone, raise the effective chain persistence length by at least a factor of 5.
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Affiliation(s)
- Klaus Becker
- Photonics and Optoelectronics Group, Department of Physics and CeNS, Ludwig Maximilians University of Munich, 80799 Munich, Germany
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