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



　　　　　　　　　　　　　　　　　　　　　　Reference

　　　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)

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