Hydrogen-Bonding-Mediated Formation of Supramolecular Rod−Coil Copolymers Exhibiting Hexagonal Columnar and Bicontinuous Cubic Liquid Crystalline Assemblies

1999 ◽  
Vol 32 (25) ◽  
pp. 8531-8537 ◽  
Author(s):  
Myongsoo Lee ◽  
Byoung-Ki Cho ◽  
Yoon-Sok Kang ◽  
Wang-Cheol Zin
Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 193
Author(s):  
Thi Huyen Do ◽  
Ho-Joong Kim ◽  
Manh Linh Nguyen ◽  
Byoung-Ki Cho

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.


Author(s):  
David M. Anderson ◽  
Tomas Landh

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.


2017 ◽  
Vol 5 (35) ◽  
pp. 9165-9173 ◽  
Author(s):  
Ling-Xiang Guo ◽  
Yu-Han Liu ◽  
Li Wang ◽  
Meng Wang ◽  
Bao-Ping Lin ◽  
...  

A variety of hydrogen-bonding induced melamine-core supramolecular discotic liquid crystals possessing hexagonal columnar, rectangular columnar and square columnar phases are described.


2017 ◽  
Vol 41 (14) ◽  
pp. 6514-6522 ◽  
Author(s):  
Yuki Arakawa ◽  
Yukito Sasaki ◽  
Kazunobu Igawa ◽  
Hideto Tsuji

A novel class of hydrogen bonding liquid crystalline benzoic acids with alkylthio groups was established and their phase transition behavior was investigated in detail.


2000 ◽  
Vol 33 (17) ◽  
pp. 6315-6320 ◽  
Author(s):  
Huilin Tu ◽  
Xinhua Wan ◽  
Yuxiang Liu ◽  
Xiaofang Chen ◽  
Dong Zhang ◽  
...  

2021 ◽  
Vol 17 (3) ◽  
pp. 285-294
Author(s):  
Mohamad Azani Abd Khadir Jalani ◽  
Hendrik O. Lintang ◽  
Siew Ling Lee ◽  
Juan Matmin ◽  
Nur Fatiha Ghazalli ◽  
...  

Gold(I) pyrazolate complex ([Au3Pz3]C10TEG) has been widely studied due to its interesting liquid crystalline properties by exhibiting the discotic hexagonal columnar arrangement. Generally, the liquid crystalline properties of the gold complex were confirmed based on their differential scanning calorimetry thermogram and polarized optical microscopy (POM) images. However, there is still no in-depth study on the phase transition in liquid crystals of [Au3Pz3]C10TEG especially on its structural change at variable temperature. In this study, the resulting liquid crystalline properties of [Au3Pz3]C10TEG upon being heated and cooled was extensively demonstrated via variable-temperature POM (VT-POM) and small angle X-ray scattering (VT-SAXS). Based on the VT-POM images, it was indicated that [Au3Pz3]C10TEG displayed a fan-shaped texture for typical arrangements of discotic hexagonal columnar of liquid crystals. Moreover, VT-SAXS results was in good agreement with the VT-POM images as it showed that [Au3Pz3]C10TEG might consist of two types of stacking system, which are ordered and disordered hexagonal discotic arrangements. Likewise, VT-SAXS analysis also demonstrated that hexagonal columnar mesophase of [Au3Pz3]C10TEG could be recovered even after the heating and cooling for two cycles.


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