These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Quantification of photoinduced order increase in liquid crystals with naphthopyran guests.
    Author: Rumi M, Cazzell SA, Kosa T, Sukhomlinova L, Taheri B, White TJ, Bunning TJ.
    Journal: Phys Rev E; 2016 Mar; 93(3):032701. PubMed ID: 27078421.
    Abstract:
    Photoinduced order-increasing phase transitions can occur in dye-liquid crystal mixtures when the photoproduct of the excitation of the dye molecules is more compatible with the liquid crystalline medium than the initial dye species. A detailed investigation of the photoinduced changes of the phase behavior and optical properties of mixtures of liquid crystals with naphthopyran guests upon exposure to light at 365 nm is presented here. In these guest-host systems, the nematic-to-isotropic phase transition temperature is increased upon irradiation. We show that the nematic range can be extended up to 2.9 °C by illumination in 5CB (4-n-pentyl-4'-cyanobiphenyl) liquid crystal mixtures. The order parameter is significantly increased by illumination at all temperatures within the nematic range and the changes are larger at higher concentrations of the guests. In particular, the illuminated guest-host mixtures exhibit order parameters close to those of the neat liquid crystal host at the same temperature relative to the clearing point. An improved understanding of the photophysical processes taking place at the molecular level in these material systems can inform the design of photoresponsive materials and enhance their potential utility in optical or photonic devices.
    [Abstract] [Full Text] [Related] [New Search]