Journal of Thermal Analysis and Calorimetry

, Volume 108, Issue 3, pp 1067–1078 | Cite as

Thermal transitions and dynamics in nanocomposite hydrogels

  • A. Kyritsis
  • A. Spanoudaki
  • C. Pandis
  • L. Hartmann
  • R. Pelster
  • N. Shinyashiki
  • J. C. Rodríguez Hernández
  • J. L. Gómez Ribelles
  • M. Monleón Pradas
  • P. Pissis
Article

Abstract

Hydrogels based on nanocomposites of statistical poly(hydroxyethyl acrylate-co-ethyl acrylate) and silica, prepared by simultaneous copolymerization and generation of silica nanoparticles by sol–gel process at various copolymer compositions and silica contents, characterized by a fine dispersion of filler, were investigated with respect to glass transition and polymer dynamics by dielectric techniques. These include thermally stimulated depolarization currents and dielectric relaxation spectroscopy, covering together broad ranges of frequency and temperature. In addition, equilibrium water sorption isotherms were recorded at room temperature (25 °C). Special attention was paid to the investigation of effects of silica on glass transition, polymer dynamics (secondary γ and βsw relaxations and segmental α relaxation), and electrical conductivity in the dry systems (xerogels) and in the hydrogels at various levels of relative humidity/water content. An overall reduction of molecular mobility is observed in the nanocomposite xerogels, in particular at high silica contents. Analysis of the results and comparison with previous work on similar systems enable to discuss this reduction of molecular mobility in terms of constraints to polymeric motion imposed by interfacial polymer–filler interactions and by the formation of a continuous silica network interpenetrated with the polymer network at filler contents higher than about 15 wt%.

Keywords

Poly(hydroxyethyl acrylate-co-ethyl acrylate)/silica hydrogels Glass transition Segmental dynamics Electrical conductivity 

References

  1. 1.
    Peppas NA, editor. Hydrogels in medicine and pharmacy, vol. I. Boca Raton, FL: CRC Press; 1986.Google Scholar
  2. 2.
    Stoy V, Kliment C. Hydrogels: speciality plastics for biomedical and pharmaceutical applications. Basel: Technomic; 1996.Google Scholar
  3. 3.
    Kyritsis A, Pissis P, Gomez Ribelles JL, Monleon Pradas M. Depolarization thermocurrent studies in poly(hydroxyethyl acrylate)/water hydrogels. J Polym Sci Part B Polym Phys. 1994;32:1001–8.CrossRefGoogle Scholar
  4. 4.
    Kyritsis A, Pissis P, Grammatikakis J. Dielectric relaxation spectroscopy in poly(hydroxyethyl acrylate)/water hydrogels. J Polym Sci Part B Polym Phys. 1995;33:1737–50.CrossRefGoogle Scholar
  5. 5.
    Kyritsis A, Pissis P, Gomez Ribelles JL, Monleon Pradas M. Polymer-water interactions in poly(hydroxyethyl acrylate) hydrogels studied by dielectric, calorimetric and sorption isotherm measurements. Polym Gels Netw. 1995;3:445–69.CrossRefGoogle Scholar
  6. 6.
    Gallego Ferrer G, Monleon Pradas M, Gomez Ribelles JL, Pissis P. Swelling and thermally stimulated depolarization currents in hydrogels formed by interpenetrating polymer networks. J Non-Cryst Solids. 1998;235–237:692–6.CrossRefGoogle Scholar
  7. 7.
    Gomez Ribelles JL, Monleon Pradas M, Gallego Ferrer G, Peidro Torres N, Perez Gimenez V, Pissis P, Kyritsis A. Poly(methyl acrylate)/poly(hydroxyethyl acrylate) sequential interpenetrating polymer networks. Miscibility and wáter sorption behavior. J Polym Sci Part B Polym Phys. 1999;37:1587–99.CrossRefGoogle Scholar
  8. 8.
    Campillo-Fernandez AJ, Salmeron Sanchez M, Sabater i Serra R, Meseguer Duenas JM, Monleon Pradas M, Gomez Ribelles JL. Water-induced (nano) organization in poly(ethyl acrylate-co-hydroxyethyl acrylate) networks. Eur Polym J. 2008;44:1996–2004.CrossRefGoogle Scholar
  9. 9.
    Kyritsis A, Spanoudaki A, Pandis C, Hartmann L, Pelster R, Shinyashiki N, Rodríguez Hernández JC, Gómez Ribelles JL, Monleón Pradas M, Pissis P. Water and polymer dynamics in poly(hydroxyl ethyl acrylate-co-ethyl acrylate) copolymer hydrogels. Eur Polym J. 2011;47:2391–2402.CrossRefGoogle Scholar
  10. 10.
    Haraguchi K. Nanocomposite hydrogels. Curr Opin Solid State Mater Sci. 2007;11:47–54.CrossRefGoogle Scholar
  11. 11.
    Janovák L, Varga J, Kemény L, Dékány I. Swelling properties of copolymer hydrogels in the presence of montmorillonite and alkylammonium montmorillonite. Appl Clay Sci. 2009;43:260–70.CrossRefGoogle Scholar
  12. 12.
    Janovák L, Varga J, Kemény L, Dékány I. The effect of surface modification of layer silicates on the thermoanalytical properties of poly(NIPAAm-co-AAm) based composite hydrogels. J Therm Anal Calorim. 2009;98:485–93.CrossRefGoogle Scholar
  13. 13.
    Rodriguez Hernandez JC, Salmeron Sanchez M, Gomez Ribelles JL, Monleon Pradas M. Polymer-silica nanocomposites prepared by sol–gel technique: nanoindentation and tapping mode AFM studies. Eur Polym J. 2007;43:2775–83.CrossRefGoogle Scholar
  14. 14.
    Rodriguez Hernandez JC, Monleon Pradas M, Gomez Ribelles JL. Properties of poly(2-hydroxyethyl acrylate)-silica nanocomposites obtained by the sol–gel process. J Non-Cryst Solids. 2008;354:1900–8.CrossRefGoogle Scholar
  15. 15.
    Pandis C, Spanoudaki A, Kyritsis A, Pissis P, Rodriguez Hernandez JC, Gomez Ribelles JL, Monleon Pradas M. Water sorption characteristics of poly(2-hydroxyethyl acrylate)/silica nanocomposite hydrogels. J Polym Sci Part B Polym Phys. 2011;49:657–68.CrossRefGoogle Scholar
  16. 16.
    Stathopoulos A, Klonos P, Kyritsis A, Pissis P, Christodoulides C, Rodriguez Hernandez JC, Monleon Pradas M, Gomez Ribelles JL. Water sorption and polymer dynamics in hybrid poly(hydroxyethyl-co-ethyl acrylate)/silica hydrogels. Eur Polym J. 2010;46:101–11.CrossRefGoogle Scholar
  17. 17.
    Kremer F, Schoenhals A, editors. Broadband dielectric spectroscopy. Berlin: Springer; 2002.Google Scholar
  18. 18.
    Donth E. The glass transition: relaxation dynamics in liquids and disordered materials. Berlin: Springer; 2001.Google Scholar
  19. 19.
    Havriliak S Jr, Havriliak SJ. Dielectric and mechanical relaxation in materials. Munich: Hanser; 1997.Google Scholar
  20. 20.
    Kripotou S, Pissis P, Savelyev YV, Robota LP, Travinskaya TV. Polymer dynamics in polyurethane/clay nanocomposites studied by dielectric and thermal techniques. J Macromol Sci Phys. 2010;49:86–110.CrossRefGoogle Scholar
  21. 21.
    Pelster R, Spanoudaki A, Kruse T. Microstructure and effective properties of nanocomposites: ferrofluids as tunable model systems. J Phys D Appl Phys. 2004;37:307–17.CrossRefGoogle Scholar
  22. 22.
    Pissis P, Kyritsis A. Electrical conductivity studies in hydrogels. Solid State Ionics. 1997;97:105–13.CrossRefGoogle Scholar
  23. 23.
    Angell CA. Relaxation in liquids, polymers and plastic crystals—strong/fragile patterns and problems. J Non-Cryst Solids. 1991;131–133:13–31.CrossRefGoogle Scholar
  24. 24.
    Fragiadakis D, Pissis P. Glass transition and segmental dynamics in poly(dimethylsiloxane)/silica nanocomposites studied by various techniques. J Non-Cryst Solids. 2007;353:4344–52.CrossRefGoogle Scholar
  25. 25.
    Kourkoutsaki Th, Logakis E, Kroutilova I, Matejka L, Nedbal J, Pissis P. Polymer dynamics in rubbery epoxy networks/polyhedral oligomeric silsequioxanes nanocomposites. J Appl Polym Sci. 2009;113:2569–82.CrossRefGoogle Scholar
  26. 26.
    Fragiadakis D, Bokobza L, Pissis P. Dynamics near the particle surface in natural rubber–silica nanocomposites. Polymer. 2011;52:3175–3182.CrossRefGoogle Scholar
  27. 27.
    Klonos P, Panagopoulou A, Bokobza L, Kyritsis A, Peoglos V, Pissis P. Comparative studies on effects of silica and titania nanoparticles on crystallization and complex segmental dynamics in poly(dimethylsiloxane). Polymer. 2010;51:5490–9.Google Scholar
  28. 28.
    Napolitano S, Wuebbenhorst M. The lifetime of the deviations from bulk behavior in polymers confined at the nanoscale. Nat Commun. 2011;2:260. doi:10.1038/incomms1259.

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2011

Authors and Affiliations

  • A. Kyritsis
    • 1
  • A. Spanoudaki
    • 1
  • C. Pandis
    • 1
  • L. Hartmann
    • 2
  • R. Pelster
    • 2
  • N. Shinyashiki
    • 3
  • J. C. Rodríguez Hernández
    • 4
  • J. L. Gómez Ribelles
    • 4
  • M. Monleón Pradas
    • 4
  • P. Pissis
    • 1
  1. 1.Department of PhysicsNational Technical University of AthensAthensGreece
  2. 2.Department of Experimental PhysicsUniversity des SaarlandesSaarbrückenGermany
  3. 3.Department of PhysicsTokai UniversityHiratsukaJapan
  4. 4.Center for BiomaterialsUniversidad Politécnica de ValenciaValenciaSpain

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