Dual role of outer epicuticular lipids in determining the wettability of dragonfly wings
Dual role of outer epicuticular lipids in determining the wettability of dragonfly wings
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DOI：
10.1016/j.colsurfb.2013.01.042
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发表时间：
2013-06-01
影响因子：
5.8
通讯作者：
Ivanova, Elena P.
中科院分区：
文献类型：
--
作者：
Nguyen, Song Ha T.;Webb, Hayden K.;Ivanova, Elena P.
许多天然表面具有超疏水性和自清洁特性，这在工业应用中是非常有益的。蜻蜓的翅膀就是这种表面的一个例子，虽然它们的一般表面结构是已知的，但它们确切的化学成分却不清楚。本文对蜻蜓翅膀膜的膜外脂质进行了表征，以探讨其对自清洁和超疏水特性的影响。在氯仿提取脂质10秒后，翅膀的水接触角下降到可接受的超疏水性阈值（150度）以下。在澳大利亚同步加速器上采集的红外光谱中，翼面上存在酰胺、酯和脂肪烃部分的特征吸收带，氯仿提取后脂肪烃部分减少。气相色谱-质谱分析表明，表皮蜡的主要成分为偶数碳正构烷烃，特别是正己烷和棕榈酸。对未经处理和氯仿提取的机翼表面进行SEM和AFM数据分析表明，提取后机翼表面形貌发生了变化；随着萃取时间的延长，表面纳米结构逐渐丧失。本文提供的数据表明，膜外脂质不仅通过其固有的疏水性有助于自清洁和超疏水性，而且还通过形成机翼表面的物理结构。这些知识将是非常有价值的重建蜻蜓翅膀结构作为一个仿生模板。(C) 2013 Elsevier B.V.版权所有
Numerous natural surfaces possess superhydrophobicity and self-cleaning properties that would be extremely beneficial when applied in industry. Dragonfly wings are one example of such surfaces, and while their general surface structure is known, their precise chemical composition is not. Here, the epicuticular lipids of dragonfly wing membranes were characterized to investigate their significance in contributing to self-cleaning and superhydrophobic properties. After just 10 s of lipid extraction using chloroform, the water contact angles exhibited by the wings decreased below the accepted threshold for superhydrophobicity (150 degrees). Infrared spectra collected at the Australian Synchrotron contained characteristic absorption bands of amide, ester and aliphatic hydrocarbons moieties on the wing surfaces, the latter of which was decreased post-extraction with chloroform. GC-MS data analysis revealed that the epicuticular wax components were dominated by n-alkanes with even-numbered carbons, especially n-hexacosane, and palmitic acid. SEM and AFM data analysis conducted on the untreated and chloroform-extracted wing surfaces demonstrated that surface topography changed after extraction; the surface nanostructure was progressively lost with extended extraction times. The data presented here indicate that epicuticular lipids contribute not only to self-cleaning and superhydrophobic properties through their inherent hydrophobic nature, but also by forming the physical structure of the wing surface. This knowledge will be extremely valuable for reconstruction of dragonfly wing structures as a biomimetic template. (C) 2013 Elsevier B.V. All rights reserved.