Photomobile polymer materials: Towards light-driven plastic motors
Photomobile polymer materials: Towards light-driven plastic motors
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DOI：
10.1002/anie.200800760
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Ikeda, Tomiki
中科院分区：
文献类型：
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作者：
Yamada, Munenori;Kondo, Mizuho;Ikeda, Tomiki
由于光是一种可以远程、即时、精确控制的良好能源，光驱动的软执行器在广泛的工业和医疗领域可以发挥重要的新应用。液晶弹性体(LCEs)是一种独特的材料，兼有液晶(LCS)和弹性体的性质，[1-3]LCEs可以通过加入光致变色分子，如偶氮苯，借助于这些生色团的光化学反应，产生大的变形，如可逆的收缩和膨胀，甚至弯曲。[4-12]在这里，我们展示了LCEs及其复合材料的新的复杂运动：仅由光驱动的塑料马达。如果材料吸收光并改变其形状或体积，它们可以将光能直接转化为机械功(光机械效应)，并且可以作为一步能量转换非常有效。此外，这些光移动材料将具有广泛的应用前景，因为它们可以通过操纵照射条件进行远程控制。LCE表现出具有协同效应的各向异性介元有序，当加热到其LC-各向同性(I)相变温度(TLC-I)以上时，导致它们沿着介元取向方向发生各向异性收缩，并通过降低TLC-I温度进行膨胀。[1，13-18]这种膨胀和收缩是由于介元排列的微观变化，随后是通过介元和聚合物链段的协同运动而发生的显著的宏观有序变化。
As light is a good energy source that can be controlled remotely, instantly, and precisely, light-driven soft actuators could play an important role for novel applications in wideranging industrial and medical fields. Liquid-crystalline elastomers (LCEs) are unique materials having both properties of liquid crystals (LCs) and elastomers,[1–3] and a large deformation can be generated in LCEs, such as reversible contraction and expansion, and even bending, by incorporating photochromic molecules, such as an azobenzene, with the aid of photochemical reactions of these chromophores.[4–12] Herein we demonstrate new sophisticated motions of LCEs and their composite materials: a plastic motor driven only by light.If materials absorb light and change their shape or volume, they can convert light energy directly into mechanical work (the photomechanical effect) and could be very efficient as a single-step energy conversion. Furthermore, these photomobile materials would be widely applicable because they can be controlled remotely just by manipulating the irradiation conditions. LCEs show an anisotropic order of mesogens with a cooperative effect, which leads them to undergo an anisotropic contraction along the alignment direction of mesogens when heated above their LC-isotropic (I) phase transition temperatures (TLC-I) and an expansion by lowering the temperature below TLC-I.[1, 13–18] The expansion and contraction is due to the microscopic change in alignment of mesogens, followed by the significant macroscopic change in order through the cooperative movement of mesogens and polymer segments.