Reversible Photoreduction as a Trigger for Photoresponsive Gels
Reversible Photoreduction as a Trigger for Photoresponsive Gels
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DOI：
10.1021/acs.chemmater.6b02677
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发表时间：
2016-09-13
影响因子：
8.6
通讯作者：
Adams, Dave J.
中科院分区：
文献类型：
--
作者：
Draper, Emily R.;Schweins, Ralf;Adams, Dave J.
本文介绍了一种新型的光响应、可逆的低分子量凝胶。所有先前的实例依赖于光异构化、闭环或二聚化。我们表明，在形成一个稳定的自由基阴离子的结果，一个？自由基阴离子的形成导致了自组装聚集体中苝双酰亚胺的堆积发生变化，导致了纤维网络的变化和凝胶流变性能的增加。流变学性质的增加对于光响应凝胶是极其罕见的;通常，照射导致凝胶到溶胶的转变，并且凝胶崩解。随着自由基阴离子在空气中衰减（这需要几个小时），原始的凝胶特性得以恢复。这种光还原可以循环多次。最后，我们表明，在图案化的凝胶的照射和非照射部分之间的机械性能是不同的。
We present here a new type of photoresponsive, reversible low molecular weight gel. All previous examples rely on a photo-isomerisation, ring-closing or,dimerization. We show that photoreduction of a perylene bisimide gelator results in the formation of a stable radical anion. The formation of the radical anion results in a change in the packing of the perylene bisimides in the self-assembled aggregates, leading to a change in fibrous network and an increase in the rheological properties of the gels. An increase in the theological properties is extremely rare for a photoresponsive gel; normally, irradiation results in a gel-to-sol transition, and the gel falling apart. As the radical anion decays, which takes several hours in air, the original gel properties are restored. This photoreduction can be cycled many times. Finally, we show that the mechanical properties are different between irradiated and nonirradiated sections in a patterned gel.