• Confinement of an antiferroelectric liquid crystal in a polymer nanonetwork: thermal and dielectric behaviour

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    • Keywords

       

      Nanonetwork; polymer confinement; antiferroelectric liquid crystal; dielectric relaxation spectroscopy.

    • Abstract

       

      We report the thermal and dielectric investigations on a liquid crystal exhibiting an antiferroelectric phase and confined in a polymer network of sub-micron dimensions. Two different photo-polymerizable monomers have beenemployed for the purpose: one of them (HDDA) is bereft of any aromatic parts, while the other (RM82) contains aromatic as well as aliphatic units and, in fact, forms a liquid crystalline phase in its monomeric state. The polymerization, whichis carried out in the presence of the liquid crystalline host, is expected to yield a nanosegregated structure for HDDA and blended structure for the RM82 case, the difference reflecting the morphologies of the networks, as evidenced by SEMimages. Surprisingly, even a small concentration of the latter polymer added to the former variety has substantial influence on the morphology. The main work focusses on calorimetry and dielectric relaxation spectroscopy of the host liquid crystal confined in these nanonetworks created by the polymers, which can be considered to form virtual surfaces with a finite anchoring energy.We have investigated the in-phase and antiphase modes in the antiferroelectric phase, and the soft mode in the paraelectric phase preceding the antiferroelectric phase. The relaxation frequencies of all these modes are substantiallyinfluenced by the network, with the results showing certain surprises in cases containing both HDDA and RM82.

    • Author Affiliations

       

      MARLIN BARAL1 A P RANJITHA1 S KRISHNA PRASAD1

      1. Centre for Nano and Soft Matter Sciences, Bengaluru 560013, India
    • Dates

       
  • Bulletin of Materials Science | News

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