Paper
20 April 2006 Photo-fluids as optical sensors and data storage materials
Author Affiliations +
Abstract
An increase in stochastic molecular vibrations of a solid due to heating above the melting point leads to a decrease in its long-range order and a loss of structural symmetry. Therefore conventional liquids are isotropic media. We report on a light-induced isothermal phase transition of polymer materials from an isotropic solid to an anisotropic liquid state in which the degree of mechanical anisotropy can be controlled by light. Whereas during irradiation by circular polarized light the materials behave as an isotropic viscoelastic fluid, they display considerable fluidity only in the direction parallel to the light field vector under linear polarized light. In this case the polymers behave visually as a liquid along one direction and as a solid in others (one-direction liquid-state), demonstrating thus extraordinarily anisotropic mechanical properties. The fluidisation phenomenon is related to photoinduced motion of azobenzene-functionalised molecular units, which can be effectively activated only when their transition dipole moments are oriented close to the direction of the light polarization. We also show that the selective excitation of chromophores orientated parallel to the light polarization not only has great influence on the anisotropy of the mechanical properties of the materials, but also induces an anisotropic expanding force, which can be used for polarization-selective opto-mechanical actuators and sensors.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Peter Karageorgiev, Dieter Neher, and Burkhard Schulz "Photo-fluids as optical sensors and data storage materials", Proc. SPIE 6192, Organic Optoelectronics and Photonics II, 61921G (20 April 2006); https://doi.org/10.1117/12.662484
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Polymers

Polarization

Solids

Liquids

Anisotropy

Chromophores

Data storage

Back to Top