Hierarchically structured superhydrophobic flowers with low hysteresis of the wild pansy (Viola tricolor) – new design principles for biomimetic materials

Beilstein Journal of Nanotechnology - Tập 2 - Trang 228-236
Anna Julia Schulte1, Damian M Droste, Kerstin Koch, Wilhelm Barthlott
1Nees Institute for Biodiversity of Plants, University of Bonn, Meckenheimer Allee 170, Bonn, Germany.

Tóm tắt

Hierarchically structured flower leaves (petals) of many plants are superhydrophobic, but water droplets do not roll-off when the surfaces are tilted. On such surfaces water droplets are in the “Cassie impregnating wetting state”, which is also known as the “petal effect”. By analyzing the petal surfaces of different species, we discovered interesting new wetting characteristics of the surface of the flower of the wild pansy (Viola tricolor). This surface is superhydrophobic with a static contact angle of 169° and very low hysteresis, i.e., the petal effect does not exist and water droplets roll-off as from a lotus (Nelumbo nucifera) leaf. However, the surface of the wild pansy petal does not possess the wax crystals of the lotus leaf. Its petals exhibit high cone-shaped cells (average size 40 µm) with a high aspect ratio (2.1) and a very fine cuticular folding (width 260 nm) on top. The applied water droplets are in the Cassie–Baxter wetting state and roll-off at inclination angles below 5°. Fabricated hydrophobic polymer replicas of the wild pansy were prepared in an easy two-step moulding process and possess the same wetting characteristics as the original flowers. In this work we present a technical surface with a new superhydrophobic, low adhesive surface design, which combines the hierarchical structuring of petals with a wetting behavior similar to that of the lotus leaf.

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Tài liệu tham khảo

10.1016/j.pmatsci.2008.07.003

10.1071/FP06139

Barthlott, 1977, Tropische und Subtropische Pflanzenwelt, 19, 367

10.1007/s004250050096

10.1006/anbo.1997.0400

10.1098/rsta.2009.0022

10.1002/adma.200904411

10.1007/978-1-4020-6697-9_7

10.1039/b712575p

Barthlott, 1981, Tropische und subtropische Pflanzenwelt, 32, 7

10.1021/ie50320a024

10.1039/tf9444000546

10.1038/nmat924

Israelachvili, 1994, Fundamentals of adhesion and interfaces, 261

10.1021/la025769z

10.1002/adma.200700934

10.1021/la703821h

10.1021/la9017536

10.1021/ja065537c

10.1021/ar900205g

10.1007/978-3-642-02525-9_42

10.1021/cm051453b

10.1021/ie071603n

10.1021/jp900594k

10.1021/la904585j

10.1002/(SICI)1521-3773(19980316)37:5<550::AID-ANIE550>3.0.CO;2-G

10.1016/j.actbio.2007.05.013

10.1088/1748-3182/3/4/046002

10.1016/j.actbio.2009.01.028

10.4161/cib.2.3.8084

Zhang, 2008, Acta Hort. (ISHS), 766, 469, 10.17660/ActaHortic.2008.766.63

10.1073/pnas.82.14.4750

10.1039/b501657f

10.1063/1.2841818

10.1016/j.ultramic.2007.04.011

10.1098/rsta.2009.0014

Fürstner, 2002, Untersuchungen zum Einfluss von Struktur und Chemie auf die Benetzbarkeit und die Selbstreinigung superhydrophober Oberflächen, 5, 151

10.1016/j.susc.2009.03.019