Design and characterization of hydrogen bond ferroelectric liquid crystals for device applications

Abstract

Liquid Crystals (LC), the captivating materials have gained utmost importance in recent years due to their wide commercial viabilities in various display applications. LC mesogenic phase is an intermediate state of accretion between crystalline solid and amorphous liquid. They are classified as thermotropic LC (temperature dependent) and lyotropic LC (solvent concentration). Friedrich Reinitzer, in the year 1888 first examined the physico-chemical properties of cholesteric liquid crystals. Complementary inter molecular hydrogen bonds are formed between a proton donor and an electron acceptor atoms of carboxylic acids. Moreover, the mesogenic properties of HBLC can be tuned easily by varying the types of bonding, constitution of donor/acceptor moieties and their molar composition. HBLC harvests a greater interest in forming novel liquid crystalline materials due to their ease of expanding the rigid rod segment of individual components. Thus it leads to the inducement of new mesogenic phases, which are not observed in the precursors. newlineHence, hydrogen bond is observed to profoundly influence the clearing points, enthalpy values and phase polymorphism exhibited by the mesogens. Considering these arguments, a successful attempt is made in designing, synthesizing, and characterizing four rod like homologues series comprising of 38 mesogens, which consists of a variety of chemical constitution including chiral substitution configured on the molecular frame and single and double hydrogen bonds. These mesogens are demonstrated for targeted specific applications namely thermistor, optical shutter, IR filter and logic gates. newline newline newline newline