2020   02   en   p.10-16 T.D. Ibragimov, A.R. Imamaliyev, G.F. Ganizade,
Dielectric, conductivity, and electro-optic properties of liquid crystal 5CB doped by single-walled carbon nanotubes


The effect of single-walled carbon nanotubes (SWCNTs) on the dielectric, conductive, and electro-optic properties of nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB) has been studied. It was shown that the additive of SWCNTs with concentration of 0.5% leads to strong interaction between SWCNTs and molecules, which increases the order parameter of 5CB. As a result, the clearing point is raised, the longitudinal component of the dielectric permittivity increases while the transverse component decreases. The incipient percolation effect promotes to the dominance of hopping electron conductivity over ionic conductivity, leading to an increase in specific conductivity. In this case, the elastic splay constant of 5CB is enhanced and, accordingly, the threshold voltage of the S-effect increases. A decrease in the Van-der-Waals interaction between molecules decreases viscosity. As a result, the flip-flop motion of molecules become easier and the switching times are also reduced.

Keywords: liquid crystal, single-walled carbon nanotubes, dielectric relaxation, electric conductivity, threshold voltage.
PACS: 64.70.mj;64.70.pv;77.84.Nh;82.70.Dd.

Received: 03.06.2020


Institute of Physics of NAS Azerbaijan 131, H. Javid ave., Baku, Azerbaijan, AZ-1143
E-mail: tdibragimov@mail.ru

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