Surfactant-induced enhancement of droplet adhesion in superhydrophobic soybean (Glycine max L.) leaves

• Oliver Hagedorn,
• Ingo Fleute-Schlachter,
• Hans Georg Mainx,
• Viktoria Zeisler-Diehl and
• Kerstin Koch

Beilstein J. Nanotechnol. 2017, 8, 2345–2356, doi:10.3762/bjnano.8.234

• applied droplets, even on superhydrophobic leaves, to reduce undesirable soil contamination by roll-off of agrochemical formulations from the plant surfaces. The wettability and morphology of soybean (Glycine max L.) leaf surfaces before and after treatment with six different surfactants (Agnique® SBO10

• epicuticular wax showed that 1-triacontanol (C30H61OH) is the main wax component of the soybean leaf surfaces. A water contact angle (CA) of 162.4° (σ = 3.6°) and tilting angle (TA) of 20.9° (σ = 10.0°) were found. Adherence of pure water droplets on the superhydrophobic leaves is supported by the hydrophilic

• reduction of the epicuticular wax structures and a change from Cassie–Baxter wetting to an intermediate wetting regime with an increase of droplet adhesion. Keywords: droplet adhesion; epicuticular wax; Glycine max L; superhydrophobic; surfactants; Introduction The cuticle, as the outermost layer of

Collembola cuticles and the three-phase line tension

• Håkon Gundersen,
• Hans Petter Leinaas and
• Christian Thaulow

Beilstein J. Nanotechnol. 2017, 8, 1714–1722, doi:10.3762/bjnano.8.172

• springtails (Collembola) are superhydrophobic, but the mechanism has not been described in detail. Previous studies have suggested that overhanging surface structures play an important role, but such structures are not a universal trait among springtails with superhydrophobic cuticles. A novel wetting

• prediction of contact angles in the observed range. The discrepancy between the contact angle predicted by simple models and those observed is especially large in the springtail Cryptopygus clavatus which changes, seasonally, from superhydrophobic to wetting without a large change in surface structure; C

• in functional surfaces with effects like self-cleaning, drag reduction and air retention [10][11][12]. The field of superhydrophobic surfaces has made extensive use of biomimetic methods, where the imitation of natural surfaces provides the basis for artificial surfaces [9][13][14]. The exact nature

Air–water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy

• Markus Moosmann,
• Thomas Schimmel,
• Wilhelm Barthlott and
• Matthias Mail

Beilstein J. Nanotechnol. 2017, 8, 1671–1679, doi:10.3762/bjnano.8.167

• , D-76344 Eggenstein-Leopoldshafen, Germany Institute of Crop Science and Resource Conservation (INRES) – Horticultural Science, University of Bonn, Auf dem Hügel 6, D-53121 Bonn, Germany 10.3762/bjnano.8.167 Abstract Underwater air retention of superhydrophobic hierarchically structured surfaces is

• interface have been limited to the micrometer regime. In this work, we utilized a nondynamic and nondestructive atomic force microscopy (AFM) method to image the interface of submerged superhydrophobic structures with nanometer resolution. Up to now, only the interfaces of nanobubbles (acting almost like

• effect; Introduction Air retention is one of the many fascinating aspects of superhydrophobic surfaces, offering promising new capabilities for technical applications [1]. Starting with the discovery of the lotus effect in 1997 [2], new fields in surface technology have been realized [3][4]. In recent

Process-specific mechanisms of vertically oriented graphene growth in plasmas

• Subrata Ghosh,
• Shyamal R. Polaki,
• Niranjan Kumar,
• Sankarakumar Amirthapandian,
• Mohamed Kamruddin and
• Kostya (Ken) Ostrikov

Beilstein J. Nanotechnol. 2017, 8, 1658–1670, doi:10.3762/bjnano.8.166

• structure and defects. Here, samples grown at 600 °C showed a (contact angle) CA of 80°, indicating hydrophilic behavior (Figure 9a). However, this value significantly increased to 134° for the sample grown at 800 °C, indicating near-superhydrophobic nature (Figure 9b). Such distinct characteristic might be

• explained by surface morphology, intersheet spacing, chemical structure, oxygen functionality and crystallinity [62]. The in-depth analysis of the CA behavior is outside the scope of this paper. The near-superhydrophobic behavior most likely originates from the effects of the improved crystallinity and

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting

• Sun-Kyu Lee,
• Sori Hwang,
• Yoon-Kee Kim and
• Yong-Jun Oh

Beilstein J. Nanotechnol. 2017, 8, 1049–1055, doi:10.3762/bjnano.8.106

• films for gas-selective membranes and due to their superhydrophobic and low-dielectric properties [18][19][20][21]. The films are also applicable in optics and photonics because they can interact with light and actively induce changes in their physical properties [22][23]. There is increasing demand for

Phospholipid arrays on porous polymer coatings generated by micro-contact spotting

• Sylwia Sekula-Neuner,
• Monica de Freitas,
• Lea-Marie Tröster,
• Tobias Jochum,
• Pavel A. Levkin,
• Michael Hirtz and
• Harald Fuchs

Beilstein J. Nanotechnol. 2017, 8, 715–722, doi:10.3762/bjnano.8.75

• the therapeutic treatment for breast and prostate cancer patients. Keeping in mind previous applications of HEMA polymer in creating superhydrophilic–superhydrophobic micropatterned surfaces for cell patterning [28] and cell-screening applications [29][30], the addition of lipid arraying to the

Biological and biomimetic materials and surfaces

• Stanislav Gorb and
• Thomas Speck

Beilstein J. Nanotechnol. 2017, 8, 403–407, doi:10.3762/bjnano.8.42

• , an observant naturalist, and a truly outstanding personality, on the occasion of his 70th birthday. One of his most important achievements was building a bridge between systematic studies of plant surfaces and the nano-/microtechnology of superhydrophobic, self-cleaning, and air-holding technical

The cleaner, the greener? Product sustainability assessment of the biomimetic façade paint Lotusan^® in comparison to the conventional façade paint Jumbosil^®

• Florian Antony,
• Rainer Grießhammer,
• Thomas Speck and
• Olga Speck

Beilstein J. Nanotechnol. 2016, 7, 2100–2115, doi:10.3762/bjnano.7.200

• paint with self-cleaning properties. Results and Discussion Test of the criterion: Biomimetic product yes or no As suggested by Antony et al. [16], clarifying whether the superhydrophobic properties of double-structured rough plant surfaces like the one of the sacred lotus (Nelumbo nucifera) have been

Surface roughness rather than surface chemistry essentially affects insect adhesion

• Matt W. England,
• Tomoya Sato,
• Makoto Yagihashi,
• Atsushi Hozumi,
• Stanislav N. Gorb and
• Elena V. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1471–1479, doi:10.3762/bjnano.7.139

• commercially available superhydrophobic coating system, which was also used to prepare a rough superhydrophilic surface, by subjecting it to vacuum UV (VUV) light treatment. A superomniphobic surface (defined here as a surface exhibiting both superhydrophobicity and superoleophobicity) was created using candle

• )9Si(OC2H5)3) were purchased from Gelest Inc. (Morrisville, PA, USA). Never WetTM (superhydrophobic coatings) was purchased from Rust-Oleum Corporation (Vernon Hills, IL, USA). All chemicals were used as received without further purification. Preparation of flat and rough sample surfaces Two smooth

• rough superhydrophobic surfaces. Base coats were first deposited onto UV-cleaned Si substrates (2 × 2 cm2 and 5 × 5 cm2), then dried in air at room temperature (25 ± 2 °C) for more than 30 min. Next, topcoats were deposited onto the surfaces and cured at 100 °C for 24 h, hereafter referred to as Never

Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

• Gabriela Ramos Chagas,
• Thierry Darmanin and
• Frédéric Guittard

Beilstein J. Nanotechnol. 2015, 6, 2078–2087, doi:10.3762/bjnano.6.212

• Gabriela Ramos Chagas Thierry Darmanin Frederic Guittard Univ. Nice Sophia Antipolis, CNRS, LPMC, UMR 7336, 06100 Nice, France; Fax: (+33)492076156; Tel: (+33)492076159 10.3762/bjnano.6.212 Abstract Materials with bioinspired superhydrophobic properties are highly desirable for many potential

• C4F9 and C6F13 chains and differences in the surface morphology depend especially on the substituent position. The polyindoles exhibited hydrophobic and superhydrophobic properties even with a very low roughness. The best results are obtained with PIndole-6-F6 for which superhydrophobic and highly

• oleophobic properties are obtained due to the presence of spherical nanoparticles and low surface energy compounds. Keywords: bioinspiration; conducting polymers; electrochemistry; nanostructures; polyindoles; superhydrophobic; Introduction The number of studies about materials with superhydrophobic

Automatic morphological characterization of nanobubbles with a novel image segmentation method and its application in the study of nanobubble coalescence

• Yuliang Wang,
• Huimin Wang,
• Shusheng Bi and
• Bin Guo

Beilstein J. Nanotechnol. 2015, 6, 952–963, doi:10.3762/bjnano.6.98

• hydrophobic/superhydrophobic surfaces [22][23][24][25][26][27]. The interaction between NBs and sample surfaces supporting them was also recently investigated. A phenomenon of NB-induced nanoindentions was reported by Wang et al. on an ultrathin polystyrene (PS) film in water [8], and was further confirmed by

The capillary adhesion technique: a versatile method for determining the liquid adhesion force and sample stiffness

• Daniel Gandyra,
• Stefan Walheim,
• Stanislav Gorb,
• Wilhelm Barthlott and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 11–18, doi:10.3762/bjnano.6.2

• cantilevers, reproducing the spring constants calibrated using other methods. Keywords: adhesion; AFM cantilever; air layer; capillary forces; hairs; measurement; micromechanical systems; microstructures; Salvinia effect; Salvinia molesta; sensors; stiffness; superhydrophobic surfaces; Introduction Surface

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• where terrestrial mechanics might apply. For example, when spiders bring with them a ball of air as they dive beneath the surface, or when two superhydrophobic surfaces interact underwater. Therefore, the first task that we face is to make clear what we mean as we try to distinguish between these two

• surfaces [68][72]. Many superhydrophobic surfaces are known for their ability to hold an air film under water for a varying time span [73][74][75]. Therefore, these surfaces could hold micro bubbles that serve as cavitation nucleating sites as in seawater. Whether this effect would occur after a long-time

Growth and structural discrimination of cortical neurons on randomly oriented and vertically aligned dense carbon nanotube networks

• Christoph Nick,
• Sandeep Yadav,
• Ravi Joshi,
• Christiane Thielemann and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2014, 5, 1575–1579, doi:10.3762/bjnano.5.169

• reported ability to tailor the hydrophilicity and hydrophobicity of such 3D aligned CNT structures over a wide range from superhydrophilic to superhydrophobic [29] the directional cell growth on such structures should be possible and would thus allow understanding these observed preferences from a surface

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• length [17]. Very large slip lengths were found on superhydrophobic surfaces [6][27][28][29][30][31]. However, more convenient methods that can increase the boundary slip length without changing surface or solution are still needed. Nanobubbles, which are bubbles with dimensions of 5–100 nm in height and

• 50–800 nm in diameter at the interface of solid and liquid, were found on some hydrophobic and superhydrophobic surfaces [14][16][32][33][34][35][36][37][38]. The nanobubbles change the interface of solid and liquid and therefore are believed to affect the drag of liquid flow. Due to the high Laplace

Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

• Elena Gorb,
• Sandro Böhm,
• Nadine Jacky,
• Louis-Philippe Maier,
• Kirstin Dening,
• Sasha Pechook,
• Boaz Pokroy and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2014, 5, 1031–1041, doi:10.3762/bjnano.5.116

• (Figure 2, Table 1). Values of the surface roughness parameters dropped by factors of 7–9, when C36 was compared with C50. Both middle-chain alkanes created surfaces with relatively similar mid-range roughness. All four wax samples showed superhydrophobic properties: apparent contact angles of water

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

• of Freiburg, Schänzlestrasse 1, 79104 Freiburg im Breisgau, Germany 10.3762/bjnano.5.93 Abstract Some plants and animals feature superhydrophobic surfaces capable of retaining a layer of air when submerged under water. Long-term air retaining surfaces (Salvinia-effect) are of high interest for

• 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

• which is the angle between the solid and the liquid at the three-phase contact line. Contact angles above 90° are considered hydrophobic while surfaces with contact angles above 150° are called superhydrophobic [6][7][8][9]. Smooth surfaces can reach a maximum contact angle of 120° [10]. Accordingly

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• composites of enhanced thermal and electrical conductivity [18][19], superhydrophobic surfaces [20], separation membranes [21] and sensors [22]. As for aligned N-CNT arrays, to mention the most recent and prominent applications, they have shown to be suitable catalysts for the reduction of oxygen in alkaline

Synthesis of boron nitride nanotubes from unprocessed colemanite

• Saban Kalay,
• Zehra Yilmaz and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2013, 4, 843–851, doi:10.3762/bjnano.4.95

• that of CNTs [6]. It has been theoretically demonstrated that BNNTs can capture ions selectively creating superhydrophobic surfaces [7][8]. Since hexagonal boron nitrides (h-BNs) have a sp2 hybridization, the BNNTs can interact with polymers possessing aromatic rings via π-π interaction. Therefore, the

Porous polymer coatings as substrates for the formation of high-fidelity micropatterns by quill-like pens

• Michael Hirtz,
• Marcus Lyon,
• Wenqian Feng,
• Andrea E. Holmes,
• Harald Fuchs and
• Pavel A. Levkin

Beilstein J. Nanotechnol. 2013, 4, 377–384, doi:10.3762/bjnano.4.44

• polymer in the wetted state [4]. Such porous HEMA substrates were used for creating superhydrophilic–superhydrophobic micropatterned surfaces for cell-patterning [6] and cell-screening applications [7][8]. Here, we present an approach for the formation of high-fidelity microarrays of three-dimensional 20

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

• physical and chemical properties of the CNTs due to the plasma process (i.e., fluorination in CF4 of the CNTs, defect-density increase and opening of the CNT caps). Oxidation of VA-CNTs: As-grown VA-CNTs are superhydrophobic [89]. In 2010, Ramos et al. [90] emphasized that a post-treatment by using oxygen

• effect [132]. The origin is the peculiar roughness and the intrinsic hydrophobic behavior of the surface. Based on this observation, the authors enhanced the superhydrophobic effect on CNTs by combining two elements: the coating of VA-CNTs with hydrophobic poly(tetrafluoroethylene) (PTFE) and the

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

• shown to be superhydrophobic and anti-adhesive for water. Other petals showing papillate cells covered with cuticular folds, such as petals of roses, were hydrophobic but of high adhesion for water [10][11]. Hierarchical structuring of different characteristics has also been found in carnivorous plants

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• therefore cannot be used to solve the problem of contrast loss. A novel approach for the construction of a renewable superhydrophobic–superhydrophilic surface was presented by Nishimoto et al. [62]. The approach is based on through-mask photocatalytic patterning of hydrophobic SAM on TiO2, followed by

• to UV light. At the end of the process a negative image of the first-step surface was obtained, consisting of superhydrophilic TiO2 domains and superhydrophobic domains anchored to alumina. In that way, the restoration of hydrophilic contrast by exposure to UV was expected not to take its toll on the

Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

• Jian-Jun Yuan and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2011, 2, 760–773, doi:10.3762/bjnano.2.84

• exploited to functionalize the nanograss film with three representative species, namely porphyrin, Au nanoparticles and titania. Of particular note, the novel silica@titania composite nanograss surface demonstrated the ability to convert its wetting behavior between the extreme states (superhydrophobic

• ambient conditions, exhibits photoresponsive surface wettability through hydrophobic modification and light irradiation [44]. However, this surface failed to be superhydrophobic (i.e., water contact angle >150°) probably due to the relatively low surface roughness. In this work, by depositing the titania

• on the preformed LPEI@silica nanograss surface, we were able to construct a smart silica@titania composite nanosurface that could switch its wetting behavior from superhydrophobic to superhydrophilic state under UV irradiation (black light, 10 mW/cm−2). As shown in Figure 10, the native silica

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

• post surfaces for which all parameters except for the surface size scale were held constant. It was found that a critical transition from “sticky superhydrophobic” (composite state with large contact angle hysteresis) to “truly superhydrophobic” (composite state with low hysteresis) takes place as the

• size of the surface features reaches 1 μm. Keywords: contact angle; hysteresis; superhydrophobic; wetting; Introduction Superhydrophobic surfaces have recently been the focus of considerable scientific interest [1][2][3][4][5][6][7][8][9][10]. This is due to the fact that artificial superhydrophobic

• surfaces are promising candidates for a number of practical applications, for example, self-cleaning windows, clothing, and also microfludic systems. Drops that come into contact with a superhydrophobic material retain a nearly spherical shape and can easily roll off. As has been shown, this effect results