The properties of liquid crystal (LCs) can be altered by incorporating guest materials. The physical properties of carbon nano tubes doped liquid crystal (CNTs/LC) and pristine LC have been investigated. The rotational viscosity of CNTs/LC was lower whereas dielectric anisotropy was almost the same as compared to pristine LC. Also the twisted nematic LC cell driven by vertical field and homogeneously aligned nematic LC cells doped with carbon nanotubes (CNTs) driven by an in-plane field were fabricated and their electro-optic characteristics were investigated. The response time of CNTs doped LC was found to be improved due to the decrease in rotational viscosity.
This work reports the elongation and subsequent dispersion of carbon nano tube (CNT) aggregates driven by the electric field in a liquid crystal (LC) medium. Longitudinal and cross sectional views of CNT aggregates were investigated in homogeneously aligned cell driven by in-plane field and homeotropic aligned cell, respectively. CNT aggregates firstly were aligned toward field line by dielectrophoretic torque and secondly they were elongated above a certain threshold field due to interaction between induced dipole moment and electric field. The CNTs aggregates elongated linearly with varying electric fields. The original morphology of the CNT aggregates was restored after the removal of the field. The evidence of a complete restoration indicated that the elasticity of CNT aggregates obeyed Hooke's Law. The elongation was fully reversible only below a certain breakdown field. Above breakdown electric field, CNT aggregates were ruptured and fragmented into small pieces and consequently CNTs got dispersed in LC medium.