Effects of the viscoelastic properties on the orientational dynamics of chromophores in low Tg guest-host polymers

Jean Charles Ribierre, Loïc Mager, Alain Fort, Stéphane Méry

Research output: Contribution to journalConference article

Abstract

In photorefractive guest-host polymers, fast orientational dynamics of push-pull chromophores are needed to obtain the so-called orientational enhancement as well as high performances. For this purpose, a better understanding of the relationships between viscoelastic properties of polymers and orientational processes of chromophores is now essential for the optimization and the development of new efficient photorefractive polymers. In the present investigation, the orientational dynamics of the chromophores are probed in details by dielectric spectroscopy, second-harmonic generation and ellipsometric techniques, in various doped polymers. The materials are based on a polyvinylcarbazole plasticized with N-ethyl carbazole, a polysiloxane functionnalized with a carbazole pendant, as well as polystyrenes with different average macromolecular weights. The temperature-dependencies of their dielectric and electro-optic responses provide information on the rotational mobility of the chromophores at a microscopic scale. These data are directly compared to the temperature-dependence of the viscoelastic properties, characterized at a macroscopic level by shear compliance measurements. The analysis reveals the strong coupling between the orientational processes of the chromophores and the polymer chain dynamics. The effects of other physical parameters (applied voltage magnitude, amount of plasticizer, average molecular weight of the polymer host) on the orientational dynamics of chromophores are also investigated in order to describe the mechanical interactions between the chromophores and the polymer host. Finally, a new way of optimization for photorefractive polymeric material properties is suggested.

Original languageEnglish
Pages (from-to)69-78
Number of pages10
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume4798
DOIs
Publication statusPublished - Dec 1 2002
EventLinear and Nonlinear Optics of Organic Materials II - Seattle, WA, United States
Duration: Jul 9 2002Jul 11 2002

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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