JCP Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

You Tube Flickr Twitter UniPHY Group iResearch App Facebook

Journal of Chemical Physics / Volume 123 / Issue 17 / ARTICLES / Polymers, Biopolymers, and Complex Systems

J. Chem. Phys. 123, 174906 (2005); http://dx.doi.org/10.1063/1.2085027 (9 pages)

Signatures of the fast dynamics in glassy polystyrene: First evidence by high-field Electron Paramagnetic Resonance of molecular guests

V. Bercu1, M. Martinelli2, C. A. Massa2, L. A Pardi2, and D. Leporini3

1Dipartimento di Fisica “Enrico Fermi,” Università di Pisa, Largo B. Pontecorvo 3, 1-56127 Pisa, Italy, and Istituto Per I processi Chimico-Fisici-Consiglio Nazionale delle Ricerche (IPCF-CNR), via G. Moruzzi 1, 1-56124 Pisa, Italy
2Istituto Per I processi Chimico-Fisici-Consiglio Nazionale delle Ricerche (IPCF-CNR), via G. Moruzzi 1, 1-56124 Pisa, Italy
3Dipartimento di Fisica “Enrico Fermi,” Università di Pisa, Largo B. Pontecorvo 3, 1-56127 Pisa, Italy and CRS-SOFT-Instituto Nazionale per la Fisica della Materia (INFM)-Consiglio Nazionale delle Ricerche (CNR), Largo B. Pontecorvo 3, 1-56127 Pisa, Italy

View MapView Map

(Received 28 July 2005; accepted 31 August 2005; published online 31 October 2005)

The reorientation of one small paramagnetic molecule (spin probe) in glassy polystyrene (PS) is studied by high-field electron paramagnetic resonance spectroscopy at two different Larmor frequencies (190 and 285 GHz). Two different regimes separated by a crossover region are evidenced. Below 180 K the rotational times are nearly temperature independent with no apparent distribution. In the temperature range of 180-220 K a large increase of the rotational mobility is observed with the widening of the distribution of correlation times which exhibits two components: (i) a deltalike, temperature-independent component representing the fraction of spin probes w which persist in the low-temperature dynamics; (ii) a strongly temperature-dependent component, to be described by a power distribution, representing the fraction of spin probes 1−w undergoing activated motion over an exponential distribution of barrier heights g(E). Above 180 K a steep decrease of w is evidenced. The shape and the width of g(E) do not differ from the reported ones for PS within the errors. For the first time the large increase of the rotational mobility of the spin probe at 180 K is ascribed to the onset of the fast dynamics detected by neutron scattering at Tf = 175±25 K.

© 2005 American Institute of Physics

Article Outline

  1. INTRODUCTION
  2. EPR BACKGROUND
    1. Line shape
    2. Model of the rotational motion
    3. Adjustable parameters
    4. Features of the HF-EPR line shape
  3. EXPERIMENTAL DETAILS
  4. RESULTS AND DISCUSSION
    1. Low temperature regime: T ⩽ 180 K
    2. Crossover regime: T ≅ 200 K
    3. High temperature regime: T ≥ 220 K
    4. Characteristic times of TEMPO in PS
  5. CONCLUSIONS

RELATED DATABASES

To view database links for this article, you need to log in.

KEYWORDS and PACS

Keywords

polymers, paramagnetic resonance, vitreous state, neutron diffraction, molecular reorientation

PACS

ARTICLE DATA

Digital Object Identifier
http://dx.doi.org/10.1063/1.2085027

PUBLICATION DATA

ISSN

0021-9606 (print)  
1089-7690 (online)

Publisher

$abstract.society.value is a Member of CrossRef American Institute of Physics

For access to fully linked references, you need to log in.
    C. A. Angell, K. L. Ngai, G. B. McKenna, P. F. McMillan, and S. W. Martin, J. Appl. Phys. 88, 3113 (2000)JAPIAU000088000006003113000001.

    L. Wu, Phys. Rev. B 43, 9906 (1991).

    G. P. Johari and M. Goldstein, J. Chem. Phys. 53, 2372 (1970)JCPSA6000053000006002372000001.

    J. Colmenero and A. Arbe, Phys. Rev. B 57, 13508 (1998).

    T. Kanaya, T. Kawaguchi, and K. Kaji, J. Chem. Phys. 104, 3841 (1996)JCPSA6000104000010003841000001.

    U. Buchenau, C. Schnfeld, D. Richter, T. Kanaya, K. Kaji, and R. Wehrmann, Phys. Rev. Lett. 73, 2344 (1994).

    U. Buchenau, C. Pecharroman, R. Zorn, and B. Frick, Phys. Rev. Lett. 77, 659 (1996).

    B. Frick and D. Richter, Phys. Rev. B 47, 14795 (1993).

    V. N. Novikov, A. P. Sokolov, B. Strube, N. V. Surovtsev, E. Duval, and A. Mermet, J. Chem. Phys. 107, 1057 (1997)JCPSA6000107000004001057000001.

    A. P. Sokolov, U. Buchenau, W. Steffen, B. Frick, and A. Wischnewski, Phys. Rev. B 52, R9815 (1995).

    L. Wu and S. R. Nagel, Phys. Rev. B 46, 11198 (1992).

    N. V. Surovtsev, J. A. H. Wiedersich, V. N. Novikov, E. Rössler, and A. P. Sokolov, Phys. Rev. B 58, 14888 (1998).

    U. Buchenau, Phys. Rev. B 63, 104203 (2001).

    E. Rössler, M. Taupitz, K. Börner, M. Schulz, and H. M. Vieth, J. Chem. Phys. 92, 5847 (1990)JCPSA6000092000010005847000001.

    M. Vogel and E. Rössler, J. Chem. Phys. 114, 5802 (2001)JCPSA6000114000013005802000001.

    M. Vogel and E. Rössler, J. Chem. Phys. 115, 10883 (2001)JCPSA6000115000023010883000001.

    N. T. Gorham, R. C. Woodward, T. G. St. Pierre, R. L. Stamps, M. J. Walker, D. Greig, and J. A. D. Matthew, J. Appl. Phys. 95, 6983 (2004)JAPIAU000095000011006983000001.

    B. Derrida, Phys. Rev. B 24, 2613 (1981).

    H. Scher and E. W. Montroll, Phys. Rev. B 12, 2455 (1975).

    H. Bässler, Phys. Rev. Lett. 58, 767 (1987).

    T. Odagaki, Phys. Rev. Lett. 75, 3701 (1995).

    B. Rinn, P. Maass, and J.-P. Bouchaud, Phys. Rev. B 64, 104417 (2001).

    R. A. Denny, D. R. Reichman, and J.-P. Bouchaud, Phys. Rev. Lett. 90, 025503 (2003).

    A. Barbieri, G. Gorini, and D. Leporini, Phys. Rev. E 69, 061509 (2004).

    M. Martinelli, C. A. Massa, L. A. Pardi, V. Bercu, and F. F. Popescu, Phys. Rev. B 67, 014425 (2003).

    A. Rockenbauer, G. Csanyi, F. Fulop, S. Garaj, L. Korecz, R. Lukacs, F. Simon, L. Forro, S. Pekker, and A. Janossy, Phys. Rev. Lett. 94, 066603 (2005).

    S. B. Orlinskii, J. Schmidt, P. G. Baranov, D. M. Hofmann, C. D. Donega, and A. Meijerink, Phys. Rev. Lett. 92, 047603 (2004).

    D. Leporini, V. Schädler, U. Wiesner, H. W. Spiess, and G. Jeschke, J. Chem. Phys. 119, 11829 (2003)JCPSA6000119000022011829000001.

    J. Kim and T. Keyes, J. Chem. Phys. 121, 4237 (2004)JCPSA6000121000009004237000001.

    C. De Michele and D. Leporini, Phys. Rev. E 63, 036702 (2001).


For access to citing articles, you need to log in.


Figures (13)

Access to article objects (figures, tables, multimedia) requires a subscription; log in to view available files.
(Access to supplementary files, where available, is free for this journal.)


Close

Google Calendar

ADVERTISEMENT

Your Recent History Recent History Help

Recently Viewed

  1. Signatures of the fast dynamics in glassy polystyrene: First evidence by high-field Electron Paramagnetic Resonance of molecular guests
  2. Efficient Monte Carlo trial moves for polypeptide simulations
  3. Coarse-grained free-energy-functional treatment of quasistatic multiscale processes in heterogeneous materials
  4. Improvement of semiempirical response properties with charge-dependent response density
  5. End-evaporation dynamics revisited
Go to AIP Home
Copyright © American Institute of Physics
close