Self-Assembling Behavior of Smart Nanocomposite System: Ferroelectric Liquid Crystal Confined by Stretched Porous Polyethylene Film

Abstract

The control and prediction of soft systems exhibiting self-organization behavior can be realized by different means but still remains a highlighted task. Novel advanced nanocomposite system has been designed by filling of a stretched porous polyethylene (PE) film with pore dimensions of hundreds of nanometers by chiral ferroelectric liquid crystalline (LC) compound possessing polar self-assembling behavior. Lactic acid derivative exhibiting the paraelectric orthogonal smectic A* and the ferroelectric tilted smectic C* phases over a broad temperature range is used as a self-assembling compound. The morphology of nanocomposite film has been checked by Atomic Force Microscopy (AFM). The designed nanocomposite has been studied by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), small and wide-angle X-ray scattering and broadband dielectric spectroscopy. The effect of a porous PE confinement on self-assembling, structural, and dielectric behavior of the chiral LC compound has been established and discussed. While the mesomorphic and structural properties of the nanocomposite are found not to be much influenced in comparison to that of a pure LC compound, the polar properties have been toughly suppressed by the specific confinement. Nevertheless, the electro-optic switching was clearly observed under applied electric field of low frequency (210 V, 19 Hz). The dielectric spectroscopy and X-ray results reveal that the helical structure of the ferroelectric liquid crystal inside the PE matrix is completely unwound, and the molecules are aligned along stretching direction. Obtained results demonstrate possibilities of using stretched porous polyolefins as promising matrices for the design of new nanocomposites.

Gold Nanorod-Induced Effects in a Mesogenic Compound 4-(trans-4-n-Hexylcyclohexyl) isothiocyanatobenzene

“…Various research reveals that nanomaterials play an important role in altering and improving the properties of LC molecules. A large number of LC-nanomaterial composites have been prepared and studied extensively to understand the effect of nanomaterials on the physical and chemical properties of LCs. ,− Dopants like quantum dots of CdSe, carbon, nanoparticles of BaTiO 3 , silver, gold, MgO, and single and multiwall carbon nanotubes were used. , Paul et al doped 0.5 wt % BaTiO 3 nanopowder in 6CHBT which led to a decrease in I–N transition and enthalpy value . Tripathi et al doped 0.6 wt % Silver nanoparticles of 5 and 100 nm size in 6CHBT LC and observed a nominal increase in I–N transition temperature and marginal decrease in dielectric anisotropy .…”