Menue

Directional Deformations in Photosensitive Azopolymers

Introduction

Azobenzene polymers have been extensively explored in the last decade as photo-deformable smart materials. They have a number of technical applications as data storage media, aligning layers in display and semiconductor technology, light-controllable artificial muscles, etc. We develop a theory of light-induced deformation of azobenzene polymers both for glassy polymers and for crosslinked azobenzene elastomers. The reorientation of azo-chromophores perpendicular to the polarization of light is found to be a self-sufficient explanation for the photo-mechanics of azo-polymers. The theory demonstrates that the light-induced stress caused by azo-reorientation is enough to deform glassy polymers irreversibly and the sign of deformation (expansion/contraction) depends on the chemical structure of the molecules. The results of the theory are in agreement with molecular dynamic simulations performed by us to study light-induced deformation of azobenzene polymers with different chemical architecture. Presently we study the effects of orientation interactions between chromophores on the light-induced deformation and the kinetics of this deformation.

Highlights:

  1. S. Loebner, N. Lomadze, A. Kopyshev, M. Koch, O. Guskova, M. Saphiannikova, S. Santer
    Light-induced deformation of azobenzene-containing colloidal spheres: Calculation and measurement of opto-mechanical stresses
    Journal of Physical Chemistry B 122 (2018) 2001-2009
  2. V. Toshchevikov, T. Petrova, M. Saphiannikova
    Kinetics of light-induced ordering and deformation in LC azobenzene-containing materials
    Soft Matter 13 (2017) 2823-2835
  3. V. Toshchevikov, J. Ilnytskyi, M. Saphiannikova
    Photoisomerization kinetics and mechanical stress in azobenzene-containing materials
    Journal of Physical Chemistry Letters 8 (2017) 1094-1098
  4. J. Ilnytskyi, A. Slyusachuk, M. Saphiannikova
    Photocontrollable self-assembly of azobenzene-decorated nanoparticles in bulk: Computer simulation study
    Macromolecules 49 (2016) 9272-9282