Aliphatic flexible spacer length controls photomechanical response in compact, ordered liquid crystalline polymer networks

POLYMER

卷:133

Article

Skandani, Amir¹  Clement, J. Arul¹  Tristram-Nagle, Stephanie²  Shankar, M. Ravi¹ 

[1] Univ Pittsburgh, Swanson Sch Engn, 3700 OHara St, Pittsburgh, PA 15261 USA

[2] Carnegie Mellon Univ, Biol Phys Grp, Phys Dept, 5000 Forbes Ave, Pittsburgh, PA 15213 USA

关键词: Photomechanical;    Azobenzene;    Liquid-crystal;   

DOI  :  10.1016/j.polymer.2017.10.050

来源: Elsevier

【 摘 要 】

The aliphatic spacer length connected to the rigid mesogenic cores is shown to control the structural organization and mechanical actuation in response to light-stimulus in azobenzene-functionalized liquid crystalline polymers networks. The spacer lengths in the mesogenic host (non-photochromic) and in the photo-active azobenzene-functionalized cross linker are parametrically varied to create monodomain liquid crystalline samples. A suite of thermomechanical, photomechanical and structural characterization is used to characterize the binary co-polymers. The photomechanical responses are compared by calculating a figure-of-merit - Photocompliance (Cp). This parameter, Cp, which characterizes the incremental strain generated in response to unit intensity of irradiation (W/cm(2)), is found to correlate strongly with the S-xray order parameter and the D-spacings. We show that compact (smaller D) and higher ordering of the mesogens that result in copolymers with longer flexible spacers manifest greater photomechanical activity. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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