A triphenylene-containing side chain liquid crystalline ladder-like polysiloxane and its highly ordered superstructure

• Published in: Liquid crystals Vol. 30; no. 3; pp. 391 - 397
• Main Authors: Ba, Chao-Yi, Shen, Zhong-Rong, Gu, Hai-Wen, Guo, Guang-Qing, Xie, Ping, Zhang, Rong-Ben, Zhu, Chuan-Feng, Wan, Li-Jun, Li, Fu-You, Huang, Chun-Hui
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.03.2003
• ISSN: 0267-8292; 1366-5855
• DOI: 10.1080/0267829031000089924

A liquid crystalline discotic triphenylene-containing side chain ladder-like polysiloxane (LPS) derivative was prepared by hydrosilylation. The superstructure was investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and isotherm surface pressure (π)-area (A) diagrams based on LB-film experiments. The XRD results suggest that the discotic triphenylene units in the side chains stack to form a columnar structure and the columns further align with each other to form a board-like superstructure because of the semi-rigidity of the ladder-like backbone. This suggestion has been confirmed by parallel nanowire-like stripes observed in the AFM image. Mixing small amounts of the corresponding low molar mass molecules with the polymer leads to a more ordered and denser columnar stacking, as shown by sharpened XRD patterns and a π-A curve with a steeper slope, higher collapse pressure and lower collapse area than those obtained either for the low molar mass molecules or the polymer individually.