CNR Istituto per lo Studio delle Macromolecole (ISMAC) , via E. Bassini 15, 20133 Milano, Italy.
ACS Appl Mater Interfaces. 2014 Apr 23;6(8):5827-34. doi: 10.1021/am500687f. Epub 2014 Apr 9.
We report broadband and quasi-omnidirectional antireflective (AR) structures inspired to the nipple arrays of moth eyes. These nanocoatings, based on thin elastomeric films, are prepared by simple self-assembly processing of a co-polymer specifically designed to this purpose, and PDMS replica molding. Typically, their surface is covered by a compact distribution of hemispherical nanodomes of about 250 nm in diameter and about 100 nm in height. When these novel nanostructures are applied on a single glass surface, a maximum of 2% transmission enhancement (equivalent to a 50% reduction of the reflected component) towards wavelengths ranging from visible to near IR region is obtained. A considerable AR power is observed also at a wide range of incident angles ranging from normal to 50°. These properties could be attributed to an optimized graded refractive index profile resulting from the randomly distributed and close-packed nanodomes. Moreover, thanks to their elastomeric nature, these crack-free films can be easily applied on glass, as stickers, and periodically replaced, thus offering the possibility of easy dirt removal from an optical device.
我们报告了受蛾眼乳头阵列启发的宽带和准各向同性抗反射（AR）结构。这些基于薄弹性体薄膜的纳米涂层是通过专门为此目的设计的共聚物的简单自组装处理以及 PDMS 复制模制来制备的。通常，其表面覆盖有大约 250nm 直径和约 100nm 高度的半球形纳米穹顶的紧密分布。当这些新型纳米结构应用于单个玻璃表面时，在从可见光到近红外区域的波长范围内获得了高达 2%的透射增强（相当于反射分量减少 50%）。在从正常到 50°的宽入射角范围内也观察到相当大的 AR 功率。这些特性可以归因于随机分布和紧密堆积的纳米穹顶产生的优化渐变折射率分布。此外，由于它们的弹性性质，这些无裂纹的薄膜可以很容易地作为贴纸应用于玻璃上，并定期更换，从而为光学器件的污垢去除提供了方便。
