Structural colour using organized microfibrillation in glassy polymer films
Structural colour using organized microfibrillation in glassy polymer films
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DOI：
10.1038/s41586-019-1299-8
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发表时间：
2019-06-20
期刊：
影响因子：
64.8
通讯作者：
Sivaniah, Easan
中科院分区：
文献类型：
--
作者：
Ito, Masateru M.;Gibbons, Andrew H.;Sivaniah, Easan
在聚合物中的应力热点处形成微观空腔和微纤丝通常是不期望的，并且是材料失效的原因。这种类型的应力开裂被溶剂加速，所述溶剂通常足够弱以基本上不溶解聚合物，但是其渗透并溶解聚合物以促进空腔和微纤维形成过程（1-3）。在这里，我们展示了聚合物薄膜中微纤维和空腔的形成可以使用驻波光学来控制和利用，以在薄膜内设计周期性应力场（4）。然后，我们可以用弱溶剂开发周期性应力场，以创建空腔和微纤维填充聚合物的交替层，我们称之为有组织的应力微纤维化。这些多层多孔结构在整个可见光谱中显示出结构颜色，并且可以通过改变薄膜显影的温度和溶剂条件来调节颜色。通过进一步使用标准的平版印刷和掩模工具，有组织的应力微纤化过程成为一种无墨的大规模彩色印刷过程，在许多灵活和透明的格式上产生分辨率高达14，000点/英寸的图像（5，6）。
The formation of microscopic cavities and microfibrils at stress hotspots in polymers is typically undesirable and is a contributor to material failure. This type of stress crazing is accelerated by solvents that are typically weak enough not to dissolve the polymer substantially, but which permeate and plasticize the polymer to facilitate the cavity and microfibril formation process(1-3). Here we show that microfibril and cavity formation in polymer films can be controlled and harnessed using standing-wave optics to design a periodic stress field within the film(4). We can then develop the periodic stress field with a weak solvent to create alternating layers of cavity and microfibril-filled polymers, in a process that we call organized stress microfibrillation. These multi-layered porous structures show structural colour across the full visible spectrum, and the colour can be tuned by varying the temperature and solvent conditions under which the films are developed. By further use of standard lithographic and masking tools, the organized stress microfibrillation process becomes an inkless, large-scale colour printing process generating images at resolutions of up to 14,000 dots per inch on a number of flexible and transparent formats(5,6).