標題: | Heterocyclic pyridine-based liquid crystals: synthesis and mesomorphic properties |
作者: | Ong, Lay-Khoon Ha, Sie-Tiong Yeap, Guan-Yeow Lin, Hong-Cheu 材料科學與工程學系 Department of Materials Science and Engineering |
關鍵字: | Pyridine;nematic;smectic A;enantiotropic |
公開日期: | 1-一月-2018 |
摘要: | A series of new calamitic liquid crystals, 4-{[(pyridin-4-yl)methylidene]amino}phenyl 4-alkoxybenzoates comprising a heterocyclic (pyridine) and two phenyl rings core system, terminal alkoxy chain, imine and ester linkers were synthesised and characterised. This series consists of nine members wherein the members differ by the length of alkoxy chain (CnH2n+1O-, where n=2, 4, 6, 8, 10, 12, 14, 16, 18). Spectral analysis results were in accordance with the expected structure. Their thermotropic behaviours were studied by using differential scanning calorimetry, optical polarising microscopy and powder X-ray diffraction techniques. A single mesophase (nematic) was observed for the first three members of the series (n=2, 4 and 6). As the alkoxy chain increased to n=8 and n=10, the nematic phase appeared together with an additional smectic A (SmA) phase. When moving from n=12 until the highest members (n=18), the nematic phase disappeared and these compounds only exhibited a single mesophase (SmA). [GRAPHICS] . |
URI: | http://dx.doi.org/10.1080/02678292.2018.1455225 http://hdl.handle.net/11536/148028 |
ISSN: | 0267-8292 |
DOI: | 10.1080/02678292.2018.1455225 |
期刊: | LIQUID CRYSTALS |
Volume: | 45 |
起始頁: | 1574 |
結束頁: | 1584 |
顯示於類別: | 期刊論文 |