Swelling Dynamics and Thermo/Electro-mechanical Effects of Liquid Crystal Elastomers

Liquid crystal elastomers (LCEs), an anisotropic gel, consist of the cross-linked polymer chain networks and liquid crystalline ordering of side chain mesogenic groups. They have attracted much attention in recent years due to their thermo-mechanical and electro-mechanical effects.

We have found that swelling properties of a LCE in an anisotropic solvent, such as low molecular weight liquid crystals (LMWLCs), are different from the well-known isotropic case. In particular, the swelling properties and temperature behaviour (thermo-mechanical property) of volume changes of LCEs swollen with LMWLCs were also anisotropic.

We investigated here the electromechanical effects in LCEs previously swollen with LMWLCs. After swelling, shape changes were measured at different voltages and temperature. Measurable shape changes were observed with small voltages (V ~ 0.5 - 1.0 V). In particular, we note that, compared to unswollen LCEs, a dramatic ~ 200 times decrease of the threshold field was found for electromechanical effects in swollen LCEs


   1)Y. Yusuf, Y. Ono, Y. Sumisaki, and S. Kai, RIMS Kokyuroku, Mathematical Aspects of Complex Fluids III, Vol.1305, pp.139-148 (2003)
   2)Yusril Yusuf, Yusuke Sumisaki, and Shoichi Kai, Chem. Phys. Lett., 382, 198-202 (2003).
   3)Y. Yusuf, Y. Ono, Y. Sumisaki, P. E. Cladis, H. R. Brand, H. Finkelmann, and S. Kai, Phys. Rev. E, 69, 021710 (2004).
   4)Y. Yusuf, P. E. Cladis, H. R. Brand, H. Finkelmann, and S. Kai, Chem. Phys. Lett., 389, 443-448 (2004).
   5)J.-H. Huh, J. Xin, Y. Yusuf, and S. Kai, J. Phys. Soc. Jpn.,74, 242-245 (2005).
   6)Y. Yusuf, J-H. Huh, P. E. Cladis, H. R. Brand, H. Finkelmann, and S. Kai, Phys. Rev. E, 71, 061702 (2005).

   Yusril Yusuf awarded 2006 Glenn H. Brown Prize

   Electro-mechanical and -optical effects of polydomain MCLCE swollen with 5CB

                      Links (other groups)

   Dr. Patricia E. Cladis
   Advance Liquid Crystal Technologies, Inc., NJ 07902, USA
   Web address: http://alct.com

   Prof. Dr. Helmut R. Brand
   Theoretische Physik III, Universitat Bayreuth, 95440 Bayreuth, Germany
   Web address: http://www.phy.uni-bayreuth.de/theo/tp3/tp3.html

   Prof. Dr. Heino Finkelmann
   Makromolekulare Chemie, Universitat Freiburg, 79104 Freiburg, Germany
   Web address: http://www.chemie.uni-freiburg.de/makro/finkelmann/finkelma.htm


     Electromechanical effect of liquid single crystal elastomer (LSCE)
        swollen with a low molecular weight liquid crystal (5CB)
        (V = 68Volt, f = 1Hz triangle wave and thickness d = 45µm)

You are a guest of