Bicontinuous Cubic and Hexagonal Columnar Liquid Crystalline Ion-Conductors at Room Temperature in Ion-Doped Dendritic Amphiphiles

Abstract

A bicontinuous cubic (Cubbi) liquid crystalline (LC) phase consisting of three dimensional (3D) conducting networks is a promising structural platform for ion-conductors. For practical applications using this fascinating LC structure, it is necessary to suppress crystallization at room temperature (RT). Herein, we report the Cubbi structure at RT and the morphology–dependent conduction behavior in ionic samples of a non-crystallizable dendritic amphiphile. In the molecular design, branched alkyl chains were used as an ionophobic part instead of crystallizable linear alkyl chains. Two ionic samples with Cubbi and hexagonal columnar (Colhex) LC phases at RT were prepared by adding different amounts of lithium salt to the amphiphile. Impedance analysis demonstrated that the Cubbi phase contributed to the faster ion-conduction to a larger extent than the Colhex phase due to the 3D ionic networks of the Cubbi phase. In addition, the temperature–dependent impedance and electric modulus data provided information regarding the phase transition from microphase-separated phase to molecularly mixed liquid phase.

Side Chain Length-Dependent Dynamics and Conductivity in Self-Assembled Ion Channels

“…■ EXPERIMENTAL SECTION Materials. Figure 1 shows the chemical structure of ILCn (n = 8, 10, 12,14,16). They are denoted as ILC8, 10, 12, 14, and 16.…”

“…References , , summarized the design strategies, synthesis, and mesomorphic behavior for various columnar ILCs. However, only a handful of investigations report the molecular mobility of columnar ILCs. , Our previous study addressed the impact of the cation headgroup (cyclic and acyclic) on the dynamics of columnar ILCs and it was observed that both the dynamics and the ionic conductivity slows down for the acyclic ILCs . On the other hand, the influence of alkyl chain length on the dynamics and charge transport in columnar ILCs remains elusive.…”

Room-Temperature, Deep-Red/NIR-Emissive, C3-Symmetric (n,π-conjugated) Columnar Liquid Crystals: C3h-Tris(keto-hydrazone)s

“…Similar behavior was noted for the next member of the series, namely, THN­(6)­7 (Figure S47a). As mentioned earlier, this behavior can be attributed to the slow response of the discogens to the heat or small enthalpy changes, which may be falling well below the recognition limit of DSC equipment . However, DSC curves of the cooling runs of the other members, namely, THN­(6)­8 , THN­(6)­9 , THN­(6)­10 , THN­(6)­11 , and THN­(6)­12 , comprise two exothermic peaks, implying that these discotics crystallize while cooling from the Col phase (Figure S47b–f).…”

“…As mentioned earlier, this behavior can be attributed to the slow response of the discogens to the heat or small enthalpy changes, which may be falling well below the recognition limit of DSC equipment. 29 For compounds belonging to THN( 6)n series, peak temperatures in the DSC traces obtained during the first heating−cooling cycles at 5 °C min −1 are given along with the enthalpies (kJ mol −1 ) of transitions. b The temperature of the phase transitions of tris(hydrazone)s belonging to the THN( 9)n (trialkoxy) series could be determined with the aid of POM only as no events were seen in the DSC traces.…”

Functional group polarity-modulated formation of liquid crystals of amphiphilic cyclodextrins

“…Liquid crystals (LCs) are characterized by the presence of ordered molecules in liquid states. These materials have revolutionized the worldwide information and display 1 industries during the last several decades and they have also found many applications in other fields such as biosensors, 2,3 proton and ion conductions 4–12 and pharmaceutical industries. 13,14…”