Orientational coupling enhancement in a carbon nanotube dispersed liquid crystal

被引:93
作者
Basu, Rajratan [1 ]
Iannacchione, Germano S. [1 ]
机构
[1] Worcester Polytech Inst, Dept Phys, Order Disorder Phenomena Lab, Worcester, MA 01609 USA
来源
PHYSICAL REVIEW E | 2010年 / 81卷 / 05期
关键词
CAPACITANCE BRIDGE; ALIGNMENT;
D O I
10.1103/PhysRevE.81.051705
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
We present a detailed study of a dilute suspension of carbon nanotubes (CNTs) in a pentylcyanobiphenyl (5CB) liquid crystal (LC) by probing the dielectric properties as a function of applied ac voltage and frequency. In principle, to minimize the elastic distortion in the nematic matrix, the monodispersed CNTs follow the nematic director without disturbing the director field significantly. A strong anchoring energy due to pi-pi electron stacking between LC-CNT molecules results in an increase in the dielectric anisotropy for the hybrid system, indicating a significant enhancement in the orientational order parameter. The frequency-dependent dielectric anisotropy for the composite system reveals the intrinsic frequency response of the LC-CNT anchoring mechanism. As a matter of consequence, the extracted value of splay elastic constant suggests that LC-CNT anchoring has an impact on the structural modification of the hybrid LC+CNT system. This strong anchoring energy stabilizes local pseudonematic domains, giving rise to a nonzero dielectric anisotropy in the isotropic phase that also shows an intrinsic frequency response.
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页数:5
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