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1. Introduction
After billions of years of evolution, nature has become a
school for scientists and engineers. Learning from nature has
long been a source of bio-inspiration for human beings in the
design and construction of multifunctional materials.
[1–3]
In
the last few decades, a great variety of biomaterials has been
Peanut Leaf Inspired Multifunctional Surfaces
Shuai Yang, Jie Ju, Yuchen Qiu, Yaxu He, Xiaolin Wang, Shixue Dou, Kesong Liu,*
and Lei Jiang
investigated.
[4–7]
These biomaterials are found to possess
multifunctional integration arising from their inherent mul-
tiscale structures.
[8–10]
Nowadays, optimized biological solu-
tions are being reformulated to create bio-inspired advanced
multifunctional materials.
[11–14]
Lotus grows in muddy swamps and ponds, but the plant's
leaves are seemingly never dirty. This is because water droplets
falling onto the leaves bead up, roll freely in all directions and
then pick up dirt particles, resulting in the so-called self-cleaning
effect or the lotus effect.
[15–17]
The cooperation of hydrophobic
epicuticular wax and multiscale structures with randomly dis-
tributed micropapillae covered by branch-like nanostructures
gives rise to the superhydrophobicity with a small sliding angle.
Inspired by the lotus leaf, a great number of man-made mate-
rials with self-cleaning property and corrosion resistance have
been fabricated through different synthesis strategies.
[18–23]
In addition to superhydrophobic surfaces with low adhe-
sion, surfaces with superhydrophobicity and high adhesion
simultaneously have also attracted much attention, such
as natural rose petal and artificial patterned paper surface
with anisotropic adhesion
[24]
or even surfaces with tunable
adhesion.
[25,26]
Here, inspired by a typical xerophate peanut
( Arachis hypogaea), which survives in arid and semi-arid
regions characterized by high temperature and low rainfall,
we discovered that the peanut leaves are superhydrophobic
and highly adhesive. Through comparing the lotus leaf with
the peanut leaf, it is observed that the sliding behavior of DOI: 10.1002/smll.201301029
Nature has long served as a source of inspiration for scientists and engineers to
design and construct multifunctional artificial materials. The lotus and the peanut are
two typical plants living in the aquatic and the arid (or semiarid) habitats, respectively,
which have evolved different optimized solutions to survive. For the lotus leaf, an air
layer is formed between its surface and water, exhibiting a discontinuous three-phase
contact line, which resulted in the low adhesive superhydrophobic self-cleaning effect
to avoid the leaf decomposition. In contrast to the lotus leaf, the peanut leaf shows high-
adhesive superhydrophobicity, arising from the formation of the quasi-continuous and
discontinuous three-phase contact line at the microscale and nanoscale, respectively,
which provides a new avenue for the fabrication of high adhesive superhydrophobic
materials. Further, this high adhesive and superhydrophobic peanut leaf is proved to
be efficient in fog capture. Inspired by the peanut leaf, multifunctional surfaces with
structural similarity to the natural peanut leaf are prepared, exhibiting simultaneous
superhydrophobicity and high adhesion towards water.
Superhydrophobic Materials
S. Yang, Y. He, Prof. K. Liu, Prof. L. Jiang
Key Laboratory of Bio-Inspired Smart Interfacial Science
and Technology of Ministry of Education
School of Chemistry and Environment
Beihang University
Beijing, 100191, PR China
E-mail: liuks@buaa.edu.cn
J. Ju, Prof. L. Jiang
Beijing National Laboratory for Molecular Sciences
Key Laboratory of Organic Solids
Institute of Chemistry
Chinese Academy of Science
Beijing, 100190, PR China
Y. Qiu
College of Chemistry
Jilin University
Changchun, 130012, PR China
Prof. X. Wang, Prof. S. Dou
Superconducting and Electronic Materials
University of Wollongong
Innovation Campus, Squires Way, North Wollongong, NSW 2500, Australia
small 2014, 10, No. 2, 294–299