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Free volume in imidazolium triflimide ([C3MIM][NTf2]) ionic liquid from positron lifetime: Amorphous, crystalline, and liquid states. J Chem Phys 2010; 133:124502. [PMID: 20886945 DOI: 10.1063/1.3487522] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Free volume from positron lifetime and pressure-volume-temperature experiments in relation to structural relaxation of van der Waals molecular glass-forming liquids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:235104. [PMID: 21393763 DOI: 10.1088/0953-8984/22/23/235104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Positron annihilation lifetime spectroscopy (PALS) is employed to characterize the temperature dependence of the free volume in two van der Waals liquids: 1, 1'-bis(p-methoxyphenyl)cyclohexane (BMPC) and 1, 1'-di(4-methoxy-5-methylphenyl)cyclohexane (BMMPC). From the PALS spectra analysed with the routine LifeTime9.0, the size (volume) distribution of local free volumes (subnanometer size holes), its mean, [v(h)], and mean dispersion, σ(h), were calculated. A comparison with the macroscopic volume from pressure-volume-temperature (PV T) experiments delivered the hole density and the specific hole free volume and a complete characterization of the free volume microstructure in that sense. These data are used in correlation with structural (α) relaxation data from broad-band dielectric spectroscopy (BDS) in terms of the Cohen-Grest and Cohen-Turnbull free volume models. An extension of the latter model allows us to quantify deviations between experiments and theory and an attempt to systematize these in terms of T(g) or of the fragility. The experimental data for several fragile and less fragile glass formers are involved in the final discussion. It was concluded that, for large differences in the fragility of different glass formers, the positron lifetime mirrors clearly the different character of these materials. For small differences in the fragility, additional properties like the character of bonds and chemical structure of the material may affect size, distribution and thermal behaviour of the free volume.
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The temperature dependence of free volume in phenyl salicylate and its relation to structural dynamics: A positron annihilation lifetime and pressure-volume-temperature study. J Chem Phys 2009; 130:144906. [DOI: 10.1063/1.3115424] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Effect of free volume and temperature on the structural relaxation in polymethylphenylsiloxane: A positron lifetime and pressure-volume-temperature study. J Chem Phys 2007; 126:024906. [PMID: 17228972 DOI: 10.1063/1.2406077] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The microstructure of the free volume and its temperature dependence in polymethylphenylsiloxane (PMPS) have been examined using positron annihilation lifetime spectroscopy (PALS) and pressure-volume-temperature experiments. The hole-free volume fraction h and the specific hole-free and occupied volumes, Vf=hV and Vocc=(1-h)V, were estimated employing the Simha-Somcynsky (SS) lattice-hole theory. From the PALS spectra analyzed with the new routine LT9.0 the hole size distribution, its mean, <nuh>, and mean dispersion, sigmah, were calculated. A comparison of <nuh> with V and Vf delivered a constant specific hole number Nh'. Using a fluctuation approach the temperature dependency of the volume of the smallest representative freely fluctuating subsystem, <VSV>, is estimated to vary from approximately 8.5 nm3 at Tg to approximately 3 nm3 at T/Tg>or=1.15. Unlike other polymers, the segmental relaxation from dielectric spectroscopy of PMPS follows the Cohen-Turnbull free volume theory almost perfectly in the temperature and pressure ranges between 243 and 279 K and 0 and approximately 100 MPa. This behavior correlates with the small mass of the SS lattice mer which indicates the high flexibility of the PMPS chain. Above 293 K and approximately 150 MPa, the free volume prediction gives relaxation times that are too small, which indicates that effects of thermal energy must be included in the analysis. To quantify the degree to which volume and thermal energy govern the structural dynamics the ratio of the activation enthalpies, Ei=R[(d ln taudT1)]i (tau-relaxation time of alpha relaxation), at constant volume V and constant pressure P, EV/EP, is frequently determined. The authors present arguments for necessity to substitute EV with EVf, the activation enthalpy at constant (hole) free volume, and show that EVf/EP changes as expected: increasing with increasing free volume, i.e., with increasing temperature and decreasing pressure. EVf/EP (=0.04-0.1) exhibits remarkably smaller values than EV/EP (=0.44-0.53), which leads to the inference that the free volume plays a distinctly larger role in dynamics than traditionally concluded from EV/EP. This conclusion is in agreement with the results of our more direct Cohen-Turnbull free volume analysis.
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Temperature and pressure dependence of the free volume in the perfluorinated polymer glass CYTOP: A positron lifetime and pressure-volume-temperature study. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/polb.21248] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Positron/positronium annihilation as a probe for chemical environments of free volume holes in fluoropolymers. POLYMER 2006. [DOI: 10.1016/j.polymer.2006.03.044] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Glass transition and free volume in the mobile (MAF) and rigid (RAF) amorphous fractions of semicrystalline PTFE: a positron lifetime and PVT study. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.04.090] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Further to the “Reply to comments on the need to reconsider traditional free volume theory for polymer electrolytes”. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2004.10.069] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Microstructure of free volume in SMA copolymers I. Free volume from Simha–Somcynsky analysis of PVT experiments. POLYMER 2005. [DOI: 10.1016/j.polymer.2004.11.083] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Comments to the paper “The need to reconsider tradional free volume theory for polymer electrolytes”. Electrochim Acta 2004. [DOI: 10.1016/j.electacta.2004.06.032] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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The size and number of local free volumes in polypropylenes: A positron lifetime and PVT study. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/polb.10621] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ortho-positronium lifetime distribution analyzed with MELT and LT and free volume in poly(?-caprolactone) during glass transition, melting, and crystallization. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/polb.10622] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ionic conductivity, glass transition, and local free volume in poly(ethylene oxide) electrolytes: Single and mixed ion conductors. J Chem Phys 2003. [DOI: 10.1063/1.1567717] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Positron Annihilation Lifetime Spectroscopy (PALS) for Interdiffusion Studies in Disperse Blends of Compatible Polymers: A Quantitative Analysis. Macromolecules 2002. [DOI: 10.1021/ma020451z] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Interdiffusion in a particle matrix system of two miscible polymers: An investigation by positron annihilation lifetime spectroscopy and differential scanning calorimetry. J Appl Polym Sci 2002. [DOI: 10.1002/app.10362] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Humidity-induced plasticization and antiplasticization of polyamide 6: A positron lifetime study of the local free volume. J Appl Polym Sci 2002. [DOI: 10.1002/app.10319] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Free volume, glass transition, and degree of branching in metallocene-based propylene/?-olefin copolymers: Positron lifetime, density, and differential scanning calorimetric studies. ACTA ACUST UNITED AC 2002. [DOI: 10.1002/polb.10108] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Free-volume variation in polyethylenes of different crystallinities: Positron lifetime, density, and X-ray studies. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/polb.10072] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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The local free volume, glass transition, and ionic conductivity in a polymer electrolyte: A positron lifetime study. J Chem Phys 2001. [DOI: 10.1063/1.1402633] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Positron experiments on the formation and growth of Guinier-Preston zones in AlZn alloys. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0305-4608/11/12/006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Local Free Volume and Structure of Polymer Gel Electrolytes on the Basis of Alternating Copolymers. J Phys Chem B 2000. [DOI: 10.1021/jp994331d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Local Free Volume in Ethylene−Vinyl Acetate Copolymers: A Positron Lifetime Study. Macromolecules 2000. [DOI: 10.1021/ma9906027] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Positron/Positronium Annihilation as a Probe for the Chemical Environment of Free Volume Holes in Polymers. Macromolecules 1999. [DOI: 10.1021/ma9904215] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Positron Lifetime Studies of Decomposition in Engineering and Laboratory 2024 (Al–Cu–Mg) and 7075 (Al–Zn–Cu–Mg) Alloys. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1521-396x(199810)169:23.0.co;2-j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Do MELT or CONTIN Programs Accurately Reveal the o-Ps Lifetime Distribution in Polymers? Analysis of Simulated Lifetime Spectra. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1521-396x(199808)168:2<333::aid-pssa333>3.0.co;2-v] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Effect of Cross-Linking on the Free-Volume Properties of Diethylene Glycol Bis(allyl carbonate) Polymer Networks: A Positron Annihilation Lifetime Study. Macromolecules 1998. [DOI: 10.1021/ma971801y] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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A positron lifetime and Doppler-broadening study of positron states and free volume in polyethylene. J Radioanal Nucl Chem 1996. [DOI: 10.1007/bf02056389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Positron lifetime studies of free volume hole size distribution in amorphous and in semi-crystalline polymers. J Radioanal Nucl Chem 1996. [DOI: 10.1007/bf02036257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Positron lifetime studies of free volume hole size distribution in glassy polycarbonate and polystyrene. ACTA ACUST UNITED AC 1996. [DOI: 10.1002/pssa.2211570218] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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O. Brümmer, G. Brauer, K. Hennig (eds). European meeting on positron studies of defects, proceedings of the international conference, wernigerode, German Dem. Rep., March 23–27, 1987. Wissenschaftliche Beiträge 1987/57(023), Martin-Luther-Universität Halle-Wittenberg, DDR-4010 Halle (Saale); Volume 1, Part 1 and 2, Volume 2, Part 1 and 2, paperback, 800 pages. Price DM 95.00/Mark der DDR 95.00, ISBN 3-86010-054-8. CRYSTAL RESEARCH AND TECHNOLOGY 1988. [DOI: 10.1002/crat.2170230907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Combined investigations of NiAl alloys by means of X-ray photoelectron spectroscopy, compton gamma scattering and positron annihilation. CRYSTAL RESEARCH AND TECHNOLOGY 1988. [DOI: 10.1002/crat.2170230320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Vacancy defects in as-grown and nº-irradiated GaP and GaAs1−xPx Studied by Positrons. CRYSTAL RESEARCH AND TECHNOLOGY 1988. [DOI: 10.1002/crat.2170230225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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