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SEM images of the natural lotus leaves (a-b) before and (c-d) after the imprint process. Angle of view: 60°.
Source publication
Hydrophobic inorganic films were obtained by direct deposition of copper or
silicon onto natural lotus leaves by ion beam sputtering deposition technique.
Scanning electron microscopy observations showed a lotus-leaf-like surface
structure of the deposited inorganic films. Hydrophobic nature of the inorganic
films on lotus leaves had been improved...
Contexts in source publication
Context 1
... leaf is famous for its superhydrophobicity and self-cleaning properties because it has microsized papillae structure and nanosized epicuticula wax on the surface. Fig. 2a and b present the scanning electron microscopy (SEM) images of typical surface morphology of fresh lotus leaves. As shown in the figures, the surfaces of the natural leaves covered with micrometer-scale pillars of 3-11 μm diameters and 7-13 μm heights and branch-like wax nanostructures of about 100 nm in diameter. The microsized ...
Context 2
... process was performed to obtain large-scale replication of the surface structures of lotus leaves. Fresh lotus leaves were used directly as nanoimprint stamps. Fig. 2c and d morphology of fresh lotus leaf peeled off the surface of polystyrene resist layer after the nanoimprint process. The micron-sized papilla structures of lotus leaves were collapsed because of their low pressure resistance. The nanoimprint experiments using fresh lotus leavers as stamps indicated that fresh lotus leaf could not be used ...
Citations
... There are numerous physical and chemical methods for fabricating the superhydrophobic coating, including sol-gel, electrodeposition, sputtering, chemical etching, chemical vapour deposition, physical vapour deposition, and electrospinning While specific coating production techniques may need costly equipment and raw materials, environmental effects and complexity frequently impede large-scale production. 20 However, electrodeposition stands out since it has various advantages over other approaches. The electrodeposition process has tremendous potential for large-scale industrial coating manufacturing. ...
Corrosion is an undesirable electrochemical reaction that leads to material degradation and affects material properties like ductility, malleability, conductivity, etc. The consequences of corrosion are machine failure, bridge failures, buildings collapse, and significant economic losses to GDP (4-5%). Furthermore, corrosion can pose serious safety risks that result in casualties which makes minimizing the effect of corrosion a great challenge. Traditional solutions like inhibitors, design modification, and paints are available to prevent corrosion but have many limitations, such as cost, durability, stability issues, and general inefficiency. In this context, a nanostructured superhydrophobic coating (SH) is gaining attention for its corrosion prevention efficiency and other broad industrial applications. The nano air pockets present in SH coating exhibit a high contact angle due to their unique combination of high surface roughness, distinctive nanostructure, and reduced surface energy. This reduces the surface area of between the corrosive substance,water droplet and the metal surface, leading to improved efficiency in resisting corrosion. In this paper, the recent advancement in electrodeposition to develop corrosion-resistant SH coatings on copper substrate and compression with other metals with their physical, chemical, and thermal stabilities are discussed. In many papers, scientists observed different types of surface morphology, texture, and surface energy, which give different tendencies to prevent surfaces from corrosion are also disscused . The constraints in fabrication and the prospects of the coating are also highlighted.
... These fibers show high hydrophilicity, affecting their ability to wetting. The mechanism of water condensation on the spider silk is Commonly biomimicked materials with SEM microstructures: a) lotus leaf, a1) SEM picture of lotus leaf, reproduced with permission from ref. [52] Copyright 2011 Elsevier, b) red rose petal, b1) SEM picture of red rose petal, reproduced with permission from ref. [53] Copyright 2008 American Chemical Society, c) Namib Desert beetle, c1) SEM picture of Namib Desert beetles back, reproduced with permission from ref. [48] under the CC-BY 2.0 license. Copyright 2010 BioMed Central ltd, d) spider's silk, d1) SEM picture of spider's silk reproduced with permission from ref. [54] Copyright 2018 Elsevier, e) Penaeus monodon shrimp, e1) SEM picture of shrimp shell cross-section reprinted from ref. [55] under the CC-BY 2.0 license. ...
A new, environmentally-friendly mindset is being forced to emerge in many areas of society, including industry and science, as a result of escalating pollution and the effects of climate change. The treatment of industrial wastewater is one of the pressing issues. The use of membrane techniques to address that problem is gaining popularity. Furthermore, biomimetics of natural surfaces frequently aids in the discovery of new and more efficient solutions. In this review, the physicochemical characteristics of hydrophobic and hydrophilic surfaces were highlighted. Moreover, methods of modification to acquire enhanced antifouling and antiwetting/self-cleaning surface properties were summarized. Additionally, recent advancements in the use of membranes modified with natural compounds for seawater desalination, oil/water separation, and dye removal from an industrial wastewater were presented. Finally, a brief discussion of future challenges in membrane science was performed.
... Yang and coworkers [162] used nanoimprinting on wood and a rose petal as master structure to create superhydrophobic wood surfaces. In [163] the authors coated the lotus leaves they used as master structures with inorganic films to directly use them as nanoimprint stamps in a hot-embossing process. ...
Biomimetic micro- and nano- structures have attracted considerable interest over the last decades for various applications ranging from optics to life sciences. The complex nature of the structures, however, presents significant challenges for fabrication and their application in real-life settings. Nanoimprint lithography could provide an interesting opportunity in this respect. This article seeks to provide an overview of what has already been achieved using nanoscale replication technologies in the field of biomimetics and will aim to highlight opportunities and challenges for nanoimprinting in this respect in order to inspire new research.
... The theoretical concept of the hydrophobicity was demonstrated ∼100 years ago by Wenzel, Cassie, and Baxter [2,3]. Since then, several research efforts have been used in those theoretical models to develop artificial hydrophobic and superhydrophobic solid surfaces by mimicking the biological surfaces [4][5][6][7][8][9][10][11][12][13][14][15][16]. Most of the scientific reports were realized the superhydrophobic surfaces by creating the micro-nano structures [4][5][6][7][8][9]. ...
... Since then, several research efforts have been used in those theoretical models to develop artificial hydrophobic and superhydrophobic solid surfaces by mimicking the biological surfaces [4][5][6][7][8][9][10][11][12][13][14][15][16]. Most of the scientific reports were realized the superhydrophobic surfaces by creating the micro-nano structures [4][5][6][7][8][9]. However, the practical applicability of the proposed superhydrophobic surfaces was limited owing to its nonflexibility, and nontransparency. ...
... After sintering, lotus leaf morphology was directly transferred with high precision to the carbon surface with water contact angle of 159°, which even exceeds the lotus leaf contact angle (157°) [24]. Dai and co-workers [63] studied the direct deposition of silicon or copper onto natural lotus leaf using ion beam sputtering deposition technique; SEM results indicated that the deposition of inorganic films led to an enhanced lotus-leaf-like structure and resulted in improved hydrophobicity compared to the inorganic film on flat silicon. ...
... Therefore, various approaches have been proposed to create an artificial superhydrophobic surface. [2][3][4][5][6][7] One of such approaches is based on imitating natural superhydrophobic surfaces. [8][9][10][11][12][13] For example, some micro=nanoscal structures have been fabricated using materials such as silicon, poly(tetrafluoroethylene) (PTFE), and carbon nanotubes. ...
Polyurethane-acrylate (PUA) is a versatile UV-curable polymer with a short curing time at room temperature, whose surface structure can be flexibly modified by applying various micropatterns. In this paper, we propose a facile and cost-effective fabrication method for the continuous production of an optically transparent PUA-based superhydrophobic thin film. Poly(dimethylsiloxane) (PDMS) was employed as a soft mold for the fabrication of PUA films through the roll-to-roll technique. In addition, nanosilica was spray-coated onto the PUA surface to further improve the hydrophobicity. The fabricated PUA thin film showed the highest static water contact angle (WCA) of ~140°. The high durability of the PUA film was also demonstrated through mechanical impacting tests. Furthermore, only ~2% of voltage loss was observed in the solar panel covered with the PUA-based superhydrophobic film. These obtained results indicate the feasibility of applying the film as a protective layer in applications requiring a high transparency and a self-cleaning effect.
... In the literature, scanning electron microscopy (SEM) images of typical surface morphology of fresh lotus leaves showed periodical distribution of lots of asperities in size of microns [24,43]. This surface morphology was believed to contribute to the super anti-adhesion ability of lotus leaves [22,23]. ...
... In nature, self-cleaning characteristic of the lotus (Nelumbo nucifera) leaf [22,23] has been a source of inspiration for scientific researchers to fabricate anti-adhesion membranes. Scanning electron microscopy (SEM) images of typical surface morphology of fresh lotus leaves showed periodical distribution of lots of asperities in size of microns [24,43]. Although such a morphology was believed to significantly contribute to its super anti-adhesion ability, the mechanisms underlying this relationship remain unrevealed. ...
The super anti-adhesion ability of lotus leaf inspires to fabricate anti-adhesion membranes. To achieve this goal, a novel approach to quantify the interfacial forces between a randomly rough particle and membranes with special surface morphology, was developed. In this study, the rough surfaces of foulant particle and membrane were firstly modeled by the modified two-variable Weierstrass-Mandelbrot (WM) function and a rigorous mathematical function, respectively. Thereafter, quantification approach based on the combination of surface element integration (SEI) method and composite Simpson’s rule was deduced. This approach was verified to be feasible to quantify the interfacial forces between a rough particle and a rough flat surface. By using this novel approach, effects of scaled amplitude and water contact angle of membrane surface on interfacial forces were investigated. It was found that, the attractive forces between foulants and membrane surface would rather weaker or even become repulsive with increase in size of asperities and surface hydrophilicity, well explaining the phenomenon regarding the super anti-adhesion ability of lotus leaf. This study gives important implications for fabrication of anti-adhesion membranes.
... The first involves carrying out chemical modification after microor nanoscale hierarchical structures are fabricated, [8][9][10][11][12] while the second approach is based on the characteristic of surface morphology especially re-entrant structures. [13][14][15][16] In the first approach, there are -silane type, -carboxylic acid type and -thiol type for chemical modification materials but they are hard to be applied to industrial application because of their high cost. ...
We describe the fabrication of hydrophobic, nanoporous, anodic alumina (NAA) by controlling its surface morphology, without chemical modification. Micro-roughness and large nanopores increase the water contact angle of the surface. Sandblasted NAA (SNAA) was fabricated by anodizing after sandblasting the aluminum surface. Water contact angles on the surfaces of SNAA and of NAA chemically modified with a hydrophobic chemical differ very little.
... Many technologies take nature as a template for design. In the case of water adhesion, or surface wetting, the leaves of the Lotus (Dai, et al., 2011) and Alchemilla (Jiang and Feng, 2010) plants are excellent examples of low wetting surfaces. Microscopic investigation of the surfaces of these leaves reveal micro-scale structures on the surface, dimples and pillars respectively. ...
The speed of an alpine ski depends on many properties, including the chemical composition of the base material, the surface structuring of the base and the complex tribology involving the base, the snow and the intermediate water layer that develops as a consequence of solar heating and friction. Using the superhydrophobic properties of some natural leaves as a template, samples of UHMWPE were hot embossed using stainless steel meshes of different mesh sizes using a hot press at constant 300 N applied force for different periods of time. It was found that as the mesh size increased, decreasing the surface feature size from 78 to 51 μm, the contact angle increased, indicating lower surface wetting and a higher degree of hydrophobicity. In the case of the 325 mesh sample, the contact angle was increased from 78.35° in the virgin untreated sample to 112.84° in the thermally patterned sample.
... During the past decades, the superhydrophobicity of lotus leaves has aroused great interest of many scientists and engineers [1][2][3][4]. Numerous researches show that many beautiful micro-papillae covered by branch-like nanostructures are distributed at regular intervals on the surface of lotus leaf and this unique hierarchical micro/ nanostructures endow it superhydrophobicity with the cooperation of hydrophobic epicuticular waxes on it [5,6]. Inspired by the lotus effect, a great variety of superhydrophobic surfaces have been fabricated on different substrates by creating hierarchical surface structures and appropriate surface chemical composition through all kinds of approaches such as template method [7,8], sol-gel [9][10][11], chemical etching [12,13], electrochemical deposition [14], electrospinning [15,16], and so on [17,18]. ...
A novel approach was developed to fabricate a lotus-leaf-like superhydrophobic surface on a copper foil by simple self-assembly method with the assistance of the porous PDMS template which was used to adjust the oxidized parts of the copper foil surface before self-assembly. The results showed a series of beautiful flower-like microstructures resulting from the self-assembly of cupric stearate that were distributed at regular intervals on the as-prepared copper foil surface similar to the papillae of lotus leaf surface. The water contact angle of the as-prepared copper surface was up to 161A degrees and its sliding angle was only 3A degrees. Its great superhydrophobicity could be kept unchanged after 6 months in air. The formation mechanism of the lotus-leaf-like structure was discussed. This simple and low-cost method is expected to be applied to design and prepare complicated superhydrophobic surfaces with beautiful regular microstructures on different substrates such as stainless steel, zinc, and so on.
