Exploiting the hierarchical morphology of single-walled and multi-walled carbon nanotube films for highly hydrophobic coatings

• Francesco De Nicola,
• Paola Castrucci,
• Manuela Scarselli,
• Francesca Nanni,
• Ilaria Cacciotti and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 353–360, doi:10.3762/bjnano.6.34

• former are smaller than the latter (about one order of magnitude), we observed that a surface hierarchy naturally occurs by depositing layer by layer a SWCNT film upon a MWCNT film. The particular two-fold hierarchical morphology of the surface, resembling that observed in lotus leaves [3] and rose

• in Table 1, may be interpreted on the basis of the microstructure characteristic dimensions S and h. In both the SWCNT/MWCNT and MWCNT/SWCNT samples the microstructure characteristic dimensions are comparable with those of lotus and rose micropapillae [2][3]. Nevertheless, in the latter the extrinsic

• showing a hierarchical morphology very similar to that of lotus leaves and rose petals. Water droplets cast on SWCNT (a), MWCNT (b), SWCNT/MWCNT (c), and MWCNT/SWCNT (d) films. Owing to the rough and porous surface of the samples, water drops exhibit different contact angle values, depending on the exact

Strain distribution due to surface domains: a self-consistent approach with respect to surface elasticity

• Javier Fuhr and
• Pierre Müller

Beilstein J. Nanotechnol. 2015, 6, 321–326, doi:10.3762/bjnano.6.30

• the edge condition introduces the need of the other surface elastic constant S12. Qualitatively the result is similar to the one shown in Figure 2. Acknowledgments We thank A. Saul for fruitful discussions. This work has been done thanks to PICS grant No. 4843 and ANR 13 BS-000-402 LOTUS Grant. (a

Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces

• Matthias J. Mayser,
• Holger F. Bohn,
• Meike Reker and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2014, 5, 812–821, doi:10.3762/bjnano.5.93

• structured, superhydrophobic, self-cleaning plant surfaces (Lotus-effect) [1][2] there has been an increasing interest in superhydrophobic surfaces [3][4][5]. Superhydrophobicity describes the extreme repellence of water by a surface. The level of water repellence is usually described by the contact angle

• surfaces, e.g., the leaves of Lotus (Nelumbo nucifera) provide very high contact angles and low hysteresis [1], the air layers that are held between the surface structures persist only for short periods of time [22]. However, for some biological surfaces like the elytra of the back swimmer Notonecta or the

The surface microstructure of cusps and leaflets in rabbit and mouse heart valves

• Xia Ye,
• Bharat Bhushan,
• Ming Zhou and
• Weining Lei

Beilstein J. Nanotechnol. 2014, 5, 622–629, doi:10.3762/bjnano.5.73

• plant leaves have been studied beginning with the lotus leaf [1][2][3]. Researchers then studied the microstructures of the India canna leaf, the rice leaf, and the leaf of Colocasia esculenta [4][5]. Subsequently, the study of surface microstructures expanded to animals. Researchers studied surface

• aortic valve cusps is shown in Figure 2. It is evident from these images that a regular cobblestone-like structure appears on the surface of the heart valve cusps. This structure is similar to the microstructure on the surface of the lotus leaf. This cobblestone-like structure is uniformly distributed on

Thermal stability and reduction of iron oxide nanowires at moderate temperatures

• Annalisa Paolone,
• Marco Angelucci,
• Stefania Panero,
• Maria Grazia Betti and
• Carlo Mariani

Beilstein J. Nanotechnol. 2014, 5, 323–328, doi:10.3762/bjnano.5.36

• maximum magnification, beam energy of 10 keV). The X-ray photoemission spectroscopy (XPS) measurements have been carried out at the Lotus laboratory at the “Università di Roma La Sapienza”, in an ultra-high vacuum (UHV) system with a base pressure of 1 × 10−10 mbar, un-monochromatized Al Kα photon source

Interaction of iron phthalocyanine with the graphene/Ni(111) system

• Lorenzo Massimi,
• Simone Lisi,
• Daniela Pacilè,
• Carlo Mariani and
• Maria Grazia Betti

Beilstein J. Nanotechnol. 2014, 5, 308–312, doi:10.3762/bjnano.5.34

• ) chambers with base pressures in the low 10−10 mbar range at the LOTUS laboratory of the Università La Sapienza (Roma). The Ni(111) single crystal was cleaned by several sputtering–annealing cycles (1 keV Ar+ for 30 min, 600 °C for 10 min). Graphene was obtained by exposing the sample, which was kept

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• also by polymer functionalization. Lau et al. [131] favored a bio-inspired approach to the problem and mimicked designs found in nature. In certain plants such as the lotus leaf, water droplets roll on the surface and remove dust particles; this is a self-cleaning behavior and is called the Lotus

Impact of cell shape in hierarchically structured plant surfaces on the attachment of male Colorado potato beetles (Leptinotarsa decemlineata)

• Bettina Prüm,
• Robin Seidel,
• Holger Florian Bohn and
• Thomas Speck

Beilstein J. Nanotechnol. 2012, 3, 57–64, doi:10.3762/bjnano.3.7

• with regard to their function. Leaves of Nelumbo nucifera (lotus) and Colocasia esculenta for example show papillate epidermal cells covered with epicuticular wax crystals [9], while petals of Viola tricolor have papillate epidermal cells covered with cuticular folds [10]. All three surfaces have been

Micro to nano: Surface size scale and superhydrophobicity

• Christian Dorrer and
• Jürgen Rühe

Beilstein J. Nanotechnol. 2011, 2, 327–332, doi:10.3762/bjnano.2.38

• was observed that the lotus leaf looses its water-repellent properties if the source of the nanoscale roughness, which originates from fine hairs with a diameter of a few nanometers, is removed [19]. In addition, hydrophobicized, microscale surfaces with posts 4 μm wide become “truly” superhydrophobic

Recrystallization of tubules from natural lotus (Nelumbo nucifera) wax on a Au(111) surface

• Sujit Kumar Dora and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2011, 2, 261–267, doi:10.3762/bjnano.2.30

• Sujit Kumar Dora Klaus Wandelt Institute of Physical and Theoretical Chemistry, Bonn University, Wegelerstrasse 12, 53115 Bonn, Germany 10.3762/bjnano.2.30 Abstract We present here the first results on the self-assembly of tubules of natural wax from lotus leaves on a single crystal Au(111

• HOPG, the tubules lie flat on Au(111). Taking into account the physical properties of HOPG and Au(111), we put forward a hypothesis which can explain the different tubule orientations on both substrates. Keywords: AFM; Au(111); lotus wax; Introduction Natural nonacosan-10-ol waxes derived from plant

• leaves have been subjected to numerous studies [1][2][3][4][5][6][7][8][9]. Electron micrograph studies by Barthlott et al. [7] demonstrated the tubule-like assembly of nonacosan-10-ol molecules on lotus (Nelumbo nucifera) leaves, whilst their crystalline nature was verified by X-ray powder diffraction

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

• Anna J. Schulte,
• Damian M. Droste,
• Kerstin Koch and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 228–236, doi:10.3762/bjnano.2.27

• 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

• superhydrophobic, low adhesive surface design, which combines the hierarchical structuring of petals with a wetting behavior similar to that of the lotus leaf. Keywords: anti-adhesive; petal effect; petal structures; polymer replication; superhydrophobic; Introduction Plant surfaces provide a large diversity of

Sorting of droplets by migration on structured surfaces

• Wilfried Konrad and
• Anita Roth-Nebelsick

Beilstein J. Nanotechnol. 2011, 2, 215–221, doi:10.3762/bjnano.2.25

• ]. Plant surfaces are also known to develop a huge variety of patterns on different length scales [11]. A prominent example are the leaf wax structures leading to superhydrophobicity and the Lotus-effect [12]. Larger structures are also common, e.g., trichomes (leaf hairs) or wart-like structures. Stomata

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• Hans J. Ensikat Petra Ditsche-Kuru Christoph Neinhuis Wilhelm Barthlott Nees Institute, University of Bonn, Meckenheimer Allee 170, 53115 Bonn, Germany Institut für Botanik, Technische Universität Dresden, Zellescher Weg 20b, 01069 Dresden, Germany 10.3762/bjnano.2.19 Abstract Lotus leaves have

• become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the ‘Lotus effect’. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the

• relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the

Superhydrophobic surfaces of the water bug Notonecta glauca: a model for friction reduction and air retention

• Petra Ditsche-Kuru,
• Erik S. Schneider,
• Jan-Erik Melskotte,
• Martin Brede,
• Alfred Leder and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 137–144, doi:10.3762/bjnano.2.17

• world [5][6]. The effective self-cleaning mechanism of the Lotus flower Nelumbo nucifera is especially well known [3]. Granting of a patent in 1998 [7], followed by the introduction of the trade mark Lotus-Effect® was the start of the realisation of biomimetic self-cleaning surfaces. Another highly

Biomimetic materials

• Wilhelm Barthlott and
• Kerstin Koch

Beilstein J. Nanotechnol. 2011, 2, 135–136, doi:10.3762/bjnano.2.16

• , structures and design principles, but the technical transformation and realization may take a much longer time. Our own example of the self cleansing abilities of lotus leaves clearly demonstrates this point: Published for the first time in 1976, patented as a technical feasibility in 1994, facade paints

• structures, often self-assembling. Another change of paradigm was caused by lotus leaves: surfaces and boundary layers. All interactions between an organism and its environment take place via its surface – be it the interaction between a solid (biological species), a liquid (e.g., water), a gas (e.g., air

• layer of our planet down to the surfaces of lotus leaves or Salvinia water ferns. And these are only two out of the 20 million species which all have secrets to be revealed: Biomimetic materials provide innovative solutions for the design of a new generation of bio inspired functional materials. Wilhelm

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

• Bharat Bhushan

Beilstein J. Nanotechnol. 2011, 2, 66–84, doi:10.3762/bjnano.2.9

• animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with

• a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been

• behavior of oil droplets on various superoleophobic surfaces created in the lab. Keywords: aquatic animals; biomimetics; drag; lotus plants; shark skin; superhydrophobicity; superoleophobicity; Introduction Biologically inspired design, adaptation, or derivation from nature is referred to as ‘biomimetics

Beilstein Journal of Nanotechnology

• Thomas Schimmel

Beilstein J. Nanotechnol. 2010, 1, 1–2, doi:10.3762/bjnano.1.1

• and technologies. Nano-photonics, quantum electronics, the lotus effect and the fascinating properties of graphene are only a few well-known examples. The Beilstein Journal of Nanotechnology provides a platform for the effective exchange and dissemination of cutting-edge results in the broad area of