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Brandenburg T, Golnak R, Nagasaka M, Atak K, Sreekantan Nair Lalithambika S, Kosugi N, Aziz EF. Impacts of Conformational Geometries in Fluorinated Alkanes. Sci Rep 2016; 6:31382. [PMID: 27527753 PMCID: PMC4985654 DOI: 10.1038/srep31382] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 07/20/2016] [Indexed: 01/21/2023] Open
Abstract
Research of blood substitute formulations and their base materials is of high scientific interest. Especially fluorinated microemulsions based on perfluorocarbons, with their interesting chemical properties, offer opportunities for applications in biomedicine and physical chemistry. In this work, carbon K-edge absorption spectra of liquid perfluoroalkanes and their parent hydrocarbons are presented and compared. Based on soft X-ray absorption, a comprehensive picture of the electronic structure is provided with the aid of time dependent density functional theory. We have observed that conformational geometries mainly influence the chemical and electronic interactions in the presented liquid materials, leading to a direct association of conformational geometries to the dissolving capacity of the presented perfluorocarbons with other solvents like water and possibly gases like oxygen.
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Affiliation(s)
- Tim Brandenburg
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Ronny Golnak
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | | | - Kaan Atak
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Sreeju Sreekantan Nair Lalithambika
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Nobuhiro Kosugi
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Emad F. Aziz
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
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Kaufman LJ. Heterogeneity in Single-Molecule Observables in the Study of Supercooled Liquids. Annu Rev Phys Chem 2013; 64:177-200. [DOI: 10.1146/annurev-physchem-040412-110033] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bulk approaches to studying heterogeneous systems obscure important details, as they report average behavior rather than the distribution of behaviors in such environments. Small-molecule and polymeric supercooled liquids, which display heterogeneity in their dynamics without an underlying structural heterogeneity that sets those dynamics, are important constituents of this category of condensed matter systems. A variety of approaches have been devised to unravel ensemble averaging in supercooled liquids. This review focuses on the ultimate subensemble approach, single-molecule measurements, as they have been applied to the study of supercooled liquids. We detail how three key experimental observables (single-molecule probe rotation, translation, and fluorescence lifetime) have been employed to provide detail on dynamic heterogeneity in supercooled liquids. Special attention is given to the potential for, but also the challenges in, discriminating spatial and temporal heterogeneity and detailing the length scales and timescales of heterogeneity in these systems.
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Affiliation(s)
- Laura J. Kaufman
- Department of Chemistry, Columbia University, New York, NY 10027
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Paul BK, Samanta A, Guchhait N. Influence of chlorine substitution on intramolecular hydrogen bond energy and ESIPT barrier: Experimental and theoretical measurements on the photophysics of 3,5-dichlorosalicylic acid. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.05.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Adhikari AN, Capurso NA, Bingemann D. Heterogeneous dynamics and dynamic heterogeneities at the glass transition probed with single molecule spectroscopy. J Chem Phys 2007; 127:114508. [PMID: 17887858 DOI: 10.1063/1.2768955] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We studied the temperature dependence of the structural relaxation in poly(vinyl acetate) near the glass transition temperature with single molecule spectroscopy from Tg-1 K to Tg+12 K. The temperature dependence of the observed relaxation times matches results from bulk experiments; the observed relaxation times are, however, 80-fold slower than those from bulk experiments at the same temperature. We attribute this factor to the size of the probe molecule. The individual relaxation times of the single molecule environments are distributed normally on a logarithmic time scale, confirming that the dynamics in poly(vinyl acetate) is heterogeneous. The width of the distribution of individual relaxation times is essentially independent of temperature. The observed full width at half maximum (FWHM) on a logarithmic time axis is approximately 0.7, corresponding to a factor of about 5-fold, significantly narrower than the dielectric spectrum of the same material with a FWHM of about 2.0 on a logarithmic time axis, corresponding to a factor of about 100-fold. We explain this narrow width as the effect of temporal averaging of single molecule fluorescence signals over numerous environments due to a limited lifetime of the probed heterogeneities, indicating that heterogeneities are dynamic. We determine a loose upper limit for the ratio of the structural relaxation time to the lifetime of the heterogeneities (the rate memory parameter) of Q<80 for the range of investigated temperatures.
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Affiliation(s)
- Aashish N Adhikari
- Department of Chemistry, Williams College, 47 Lab Campus Drive, Williamstown, Massachusetts 01267, USA
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Stracke F, Blum C, Becker S, Müllen K, Meixner AJ. Correlation of emission intensity and spectral diffusion in room temperature single-molecule spectroscopy. Chemphyschem 2007; 6:1242-6. [PMID: 15929161 DOI: 10.1002/cphc.200400436] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Frank Stracke
- Fraunhofer Institute for Biomedical Engineering, Ensheimer Str. 48, 66386 St. Ingbert, Germany.
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Lippitz M, Kulzer F, Orrit M. Statistical evaluation of single nano-object fluorescence. Chemphyschem 2006; 6:770-89. [PMID: 15884060 DOI: 10.1002/cphc.200400560] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Single nano-objects display strong fluctuations of their fluorescence signals. These random and irreproducible variations must be subject to statistical analysis to provide microscopic information. We review the main evaluation methods used so far by experimentalists in the field of single-molecule spectroscopy: time traces, correlation functions, distributions of "on" and "off" times, higher-order correlations. We compare their advantages and weaknesses from a theoretical point of view, illustrating our main conclusions with simple numerical simulations. We then review experiments on different types of single nano-objects, the phenomena which are observed and the statistical analyses applied to them.
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Affiliation(s)
- Markus Lippitz
- Molecular Nano-Optics and Spins, Huygens Laboratory, Leiden Institute of Physics (LION), Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
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Vallée RAL, Tomczak N, Vancso GJ, Kuipers L, van Hulst NF. Fluorescence lifetime fluctuations of single molecules probe local density fluctuations in disordered media: A bulk approach. J Chem Phys 2005; 122:114704. [PMID: 15836240 DOI: 10.1063/1.1861881] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigated the nanometer scale mobility of polymers in the glassy state by monitoring the dynamics of embedded single fluorophores. Recently we reported on fluorescence lifetime fluctuations which reflect the segmental rearrangement dynamics of the polymer in the surroundings of the single molecule probe. Here we focus on the nature of these fluorescence lifetime fluctuations. First the potential role of quenching and molecular conformational changes is discussed. Next we concentrate on the influence of the radiative density of states on the spontaneous emission of individual dye molecules embedded in a polymer. To this end we present a theory connecting the effective-medium theory to a cell-hole model, originating from the Simha-Somcynsky free-volume theory. The relation between the derived distributions of free volume and fluorescence lifetime allows one to determine the number of segments involved in the local rearrangement directly from experimental data. Results for two different polymers as a function of temperature are presented.
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Affiliation(s)
- R A L Vallée
- Applied Optics Group, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
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Vallée RAL, Van der Auweraer M, De Schryver FC, Beljonne D, Orrit M. A Microscopic Model for the Fluctuations of Local Field and Spontaneous Emission of Single Molecules in Disordered Media. Chemphyschem 2005; 6:81-91. [PMID: 15688651 DOI: 10.1002/cphc.200400439] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We develop a microscopic model to describe the observed temporal fluctuations of the fluorescence lifetime of single molecules embedded in a polymer at room temperature. The model represents the fluorescent probe and the macromolecular matrix on the sites of a cubic lattice and introduces voids in the matrix to account for its mobility. We generalize Lorentz's approach to dielectrics by considering three domains of electrostatic interaction of the probe molecule with its nanoenvironment: (1) the probe molecule with its elongated shape and its specific polarizability, (2) the first few solvent shells with their discrete structure and their inhomogeneity, (3) the remainder of the solvent at larger distances, treated as a continuous dielectric. The model is validated by comparing its outcome for homogeneous systems with those of existing theories. When realistic inhomogeneities are introduced, the model correctly explains the observed fluctuations of the lifetimes of single molecules. Such a comparison is only possible with single-molecule observations, which provide a new access to local field effects.
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Affiliation(s)
- Renaud A L Vallée
- Laboratory for Spectroscopy and Photochemistry, Catholic University of Leuven, Celestijnenlaan 200 F, 3001 Leuven, Belgium.
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Ito S, Aoki H. Nano-Imaging of Polymers by Optical Microscopy. POLYMER ANALYSIS POLYMER THEORY 2005. [DOI: 10.1007/b135562] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Tomczak N, Vallée RA, van Dijk EM, Garcı́a-Parajó M, Kuipers L, van Hulst NF, Julius Vancso G. Probing polymers with single fluorescent molecules. Eur Polym J 2004. [DOI: 10.1016/j.eurpolymj.2004.01.045] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Vallée R, Tomczak N, Kuipers L, Vancso G, van Hulst N. Effect of solvent on nanoscale polymer heterogeneity and mobility probed by single molecule lifetime fluctuations. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2003.11.086] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Vallée RAL, Tomczak N, Kuipers L, Vancso GJ, van Hulst NF. Single molecule lifetime fluctuations reveal segmental dynamics in polymers. PHYSICAL REVIEW LETTERS 2003; 91:038301. [PMID: 12906460 DOI: 10.1103/physrevlett.91.038301] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2003] [Indexed: 05/24/2023]
Abstract
We present a single molecule fluorescence study that allows one to probe the nanoscale segmental dynamics in amorphous polymer matrices. By recording single molecular lifetime trajectories of embedded fluorophores, peculiar excursions towards longer lifetimes are observed. The asymmetric response is shown to reflect variations in the photonic mode density as a result of the local density fluctuations of the surrounding polymer. We determine the number of polymer segments involved in a local segmental rearrangement volume around the probe. A common decrease of the number of segments with temperature is found for both investigated polymers, poly(styrene) and poly(isobutylmethacrylate). Our novel approach will prove powerful for the understanding of the nanoscale rearrangements in functional polymers.
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Affiliation(s)
- R A L Vallée
- Applied Optics Group, and Materials Science and Technology of Polymers, MESA+ Research Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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