New Liquid Crystals Based on Terminal Fatty Chains and Polymorphic Phase Formation from Their Mixtures

Crystals

Noha S. Bedowr¹  Fowzia S. Alamro²  Nada S. Al-Kadhi²  Magdi M. Naoum³  Hoda A. Ahmed³  Ayman M. Mostafa⁴ 

[1] Chemistry Department, College of Sciences, Taibah University, Yanbu 30799, Saudi Arabia;Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia;Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt;Laser Technology Unit, Centre of Excellent for Advanced Science, National Research Centre, Giza 12622, Egypt;

关键词: mesomorphic properties;    smectic phases;    fatty acid liquid crystals;    geometrical structures;    binary phase diagram;    polymorphic phases;   

DOI  :  10.3390/cryst12030350

来源: DOAJ

【 摘 要 】

The physical and chemical properties of three new liquid crystalline derivatives, based on an azomethine core with low-temperature mesophase—namely (4-methoxybenzylideneamino) phenyl palmitate (I), (4-methoxybenzylideneamino) phenyl oleate (II), and (4-methoxybenzylideneamino) phenyl linoleate (III)—were prepared and physically examined using experimental methodologies. Elemental analysis, FT-IR, and NMR spectroscopy were used to confirm their molecular structure. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) were used to investigate their mesomorphic activity. The results revealed that compound (I) is monotropic smectogenic, possessing the smectic A mesophase, whereas the other two analogues were shown to possess the SmA phase enantiotropically. Two of the saturated and unsaturated prepared derivatives (namely I and II) were used to construct their phase diagram. The eutectic composition of the mixture examined showed a slight enhancement of the stability of the smectic A phase. Polymorphic phases were produced at the eutectic composition of the binary phase diagram of the derivative II with the 4-n-dodecyloxy benzoic acid component.

【 授权许可】

Unknown