Behl Marc, Lendlein Andreas
Center for Biomaterial Development, Institute of Polymer Research, GKSS Research Center Geesthacht, Kantstr. 55, D-14513 Teltow, Germany.
Soft Matter. 2006 Dec 13;3(1):58-67. doi: 10.1039/b610611k.
The ability of polymers to move actively in response to an external stimulus such as heat or light is of high scientific and technological significance. In any instance stimuli-responsive effects on the molecular level are converted into macroscopic movement, whereby generally two different moving behaviors have to be differentiated for polymer-based materials: the shape-memory effect and the shape-changing capability. Basic concepts for the molecular design of suitable polymer architectures for shape-memory polymers as well as tailored programming processes are presented. The thermally-induced shape-memory effect of polymers is described as well as the extension of this concept to other stimuli than heat. Indirect actuation of the thermally-induced effect by IR-irradiation, electric current, humidity or alternating magnetic fields are outlined as well as recent work on light-induced shape-memory polymers. For shape-changing polymers, two basic concepts are presented: shape changes occurring during phase orientation of liquid crystal elastomers (LCE) and the photomechanical effect based on photoisomerization of moieties, such as azo-groups incorporated in suitable polymer systems.
聚合物能够响应热或光等外部刺激而主动移动，这具有很高的科学和技术意义。在任何情况下，分子水平上的刺激响应效应都会转化为宏观运动，因此对于基于聚合物的材料，通常必须区分两种不同的移动行为：形状记忆效应和形状改变能力。本文介绍了用于形状记忆聚合物的合适聚合物结构的分子设计基本概念以及定制的编程过程。描述了聚合物的热致形状记忆效应以及将这一概念扩展到除热以外的其他刺激。概述了通过红外辐射、电流、湿度或交变磁场对热致效应的间接驱动以及光致形状记忆聚合物的最新研究成果。对于形状改变聚合物，介绍了两个基本概念：液晶弹性体（LCE）相取向过程中发生的形状变化以及基于诸如掺入合适聚合物体系中的偶氮基团等部分的光异构化的光机械效应。
