Study of dielectric parameters of liquid crystal elastomer

Abstract

Liquid crystal elastomers exhibit several interesting phenomena like elastic response, shape memory effect and mechanical actuation triggered by external stimuli and have got much importance among all types of actuated materials. In the present study, we synthesised nematic liquid crystal elastomers (NLCEs) by using Finkelmann procedure. The chemical structure of elastomers is confirmed by Fourier transform infrared spectroscopy. The dielectric response of NLCEs and the monomer used in its synthesis has been studied in the frequency range 20 Hz to 1 MHz. The effect of bias on dielectric response of NLCE and its comparison with its liquid crystal analogue is also reported.

Study of the optical, thermal, and mechanical properties of nematic liquid crystal elastomers

“…The peaks obtained near 3000 cm −1 was due to aromatic stretching, the peak obtained near 1732 cm −1 was due to the stretching of the carbonyl group, the peak obtained at 1606 cm −1 was due to the bending of C=C, the peak obtained at 1512 was due to the stretching of =C=, and the peak obtained at around 1200 cm −1 was due to the C−C stretching. These peaks validated the presence of all the functional groups that form NLCE and hence confirm the formation of NLCE [43].…”

“…The different physical properties of LCE have been studied by various researchers [35][36][37][38][39][40][41][42][43][44][45], but the current applications of the material show that the research work that has so far been done on it is very insufficient. In the present study, an attempt was made to investigate the optical, thermal, and mechanical properties of monodomain NLCE so as to understand the physical behavior of this material and to develop new applications of it.…”

Properties of Nematic Liquid Crystals Doped with CdSe/ZnS Semiconductor Nanoparticales

“…Диэлектрическая спектроскопия является одним из наиболее подходящих методов для измерения диэлектри-ческой проницаемости и диэлектрических потерь в НЖК с высокой точностью и чувствительностью [22][23][24].…”

Influence of Liquid Crystallinity and Mechanical Deformation on the Molecular Relaxations of an Auxetic Liquid Crystal Elastomer

“…For LCEs, there have been relatively few studies focusing on molecular relaxation behavior [ 37 , 38 , 39 ]. The nomenclature for glass-transition-related relaxation dynamics of LCEs typically follows that used for side-chain liquid crystal polymers (SCLCPs).…”

“…The structural ( ) relaxation in SCLCPs involves the backbone polymer segments and is directly related to the glass transition [ 22 , 40 ]. The process has been observed in both SCLCPs [ 22 , 41 , 42 , 43 ] and LCEs [ 37 , 38 , 39 ] and is typically slower than the relaxation, follows a VFT dependence, and is attributed to reorientation of the mesogenic units around the polymer backbone. The faster secondary relaxations, typically termed and are generally assigned to motions of the mesogenic units, where the relaxation is typically assigned to fluctuations of the mesogen around its molecular long axis [ 22 , 41 , 44 , 45 ], and the relaxation is assigned to motions of either the spacer unit, or the terminal group of the side-chain mesogen [ 40 , 41 ].…”