Determination of elastic constants of a binary system (7CPB+9.CN) showing nematic, induced smecticA_dand re-entrant nematic phases

Abstract

The temperature variation of the splay and bend elastic constants of a binary system exhibiting nematic-induced smectic A d and re-entrant nematic phases measured by electric field-induced Freedericksz transition method has been reported. As bend deformation is not permitted in the smectic A phase, bend elastic constant (K 33 ) could only be determined in the nematic and re-entrant nematic phases. In both the nematic phases, the splay elastic constant has the same order of magnitude and does not show any pretransitional effect. However, in the induced smectic A d phase, the value of K 11 is about one to two orders higher than that in the nematic phases. The bend elastic constant shows a strong pretransitional effect near the nematic-smectic and smectic-re-entrant nematic phase transitions. The influence of the presence of the induced smectic phase is observed even in those mixtures which have no induced smectic phases. As the smectic phase is approached, the ratio K 33 /K 11 increases rapidly and diverges to infinity.

Binary Liquid Crystal Mixtures Based on Schiff Base Derivatives with Oriented Lateral Substituents

“…Mesomorphic behavior of mesogenic groups may be greatly modified upon the mixing of individual compounds. It is well known that forming a mixture of two or more liquid crystal components leads to tuning the needed properties of interest [24][25][26][27][28][29][30][31][32][33]. An example is the mixing of two non-mesomorphic compounds in order to reduce its melting point, which has gained wide use in many applications.…”

Synthesis, Mesomorphic and Computational Characterizations of Nematogenic Schiff Base Derivatives in Pure and Mixed State

“…Decrement of the melting temperatures of the LCs and broadening their mesophase range are important goals for many practical applications. One way to achieve a low melting point is the mixing of compounds possessing various molecular shapes and characteristics in binary systems [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. The mesomorphic properties are greatly modified upon the mixing of individual components.…”

Optical and Thermal Investigations of New Schiff Base/Ester Systems in Pure and Mixed States

“…The mixtures of LC show mesophase transitions and thermal properties that differ from their individual components. Mixing of two or more LC components leads to tuning the needed characteristics of interest [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. Moreover, the binary LC mixtures could be better established for many fields in certain applications [ 43 ].…”