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

被引：8

作者：

Skandani, Amir ^{[1
]}

Clement, J. Arul ^{[1
]}

Tristram-Nagle, Stephanie ^{[2
]}

Shankar, M. Ravi ^{[1
]}

机构：

[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

来源：

POLYMER | 2017年 / 133卷

基金：

美国国家科学基金会; 美国安德鲁·梅隆基金会;

关键词：

Photomechanical; Azobenzene; Liquid-crystal; SIDE-CHAIN; PHOTOINDUCED ALIGNMENT; THERMAL-ISOMERIZATION; AZOBENZENE MOIETIES; OPTICAL ANISOTROPY; BEHAVIOR; ACTUATORS; GLASSY; FILMS; REORIENTATION;

D O I：

10.1016/j.polymer.2017.10.050

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

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.

引用

页码：30 / 39

页数：10

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