Electrically induced changes in polymer dispersed liquid crystals

This letter reports the changes induced in polymer dispersed liquid crystal films by applying high intensity electric fields (charge process). It has been observed that lower reorientation fields and sharper OFF-ON transitions characterize samples after the charge process. Scanning electron microscopy and dielectric investigation show that the charge process induces both a morphology and a dielectric variation in films. Nevertheless a reduction in the surface anchoring energy of the liquid crystal at droplet interface has been postulated as the changes in the dielectric properties and droplet size cannot entirely justify the enhancement of electro-optical properties. The role played by the temperature at which the charge process is performed is also discussed. (C) 2000 American Institute of Physics. [S0003-6951(00)02220-8].