Lotus leaf

In addition to popular mesoporous silica materials, mesoporous silica supports with various morphologies have also been used for protein immobilization. Tang and coworkers synthesized lotus-leaf-like silica flakes with a three-dimensionally connected nanoporous structure and controllable thickness, which were used for immobilization of ribonuclease A [126]. The synthesized silica flakes have a thickness of200 nm, and a diameter of 3 mm, showing a much higher initial adsorbing rate of... 

Nelumbium nuciferum Gaertner N. speclosum Willd. Lian, He Ye (East Indian lotus) (leaf) Nuciferine, roemerine, anonaine, O-nornuciferine, liriodenine, anneparine, dihydronuciferine, pronuciferine, N-methylcoclaurine, N-methylisococlaurine.33 Relaxing effect on smooth muscles, increase essential body energies. 

Figure 4.13 Wetting versus nonwetting, (a) The water drop on a lotus leaf with hydrophobic surface leadingto a large contact angle [204]. (b) The water drop on a glass surface with hydrophilic properties leading to a small contact angle [205].

EXHIBIT 26.2 Lotus Leaf. The leaf repels water, a feature that is often sought after in man-made solutions. 

The absorbency was found to be decreased with the reduction in particle size (Fig. 19.42]. This may be elucidated by the example of lotus leaf effect. Distribution of nano chitosan particles as a thin layer over and beneath the surface may roll out the water droplets. Nevertheless, the absorbency of nano chitosan-treated samples is still within the tolerable limits of conventional wet processing conditions since this rise in water drop penetration time is due to the initial resistance offered by nano chitosan particles and not due to the hydrophobicity. 

THE LOTUS PLANT GROWS in aquatic environments. In order to thrive in such an environment the surface of a lotus leaf is highly water repellent. Scientists call surfaces with this property superhydrophobic. The superhydrophobic character of the lotus leaf not only allows it to float on water but also causes... 

Because spheres have the smallest surface area for their volume. Water droplets assume an almost spherical shape. This explains the tendency of water to bead up when it contacts a surface made of nonpolar molecules, like a lotus leaf or a newly waxed car. 

Latthe, S.S., Terashima, C., Nakata, K., Fujishima, A., 2014. Superhydrophobic surfaces developed by mimicking hierarchical surface morphology of lotus leaf— review. Molecules 19, 4256-1283. 

The Teijin Company in Japan developed a fabric named Snper-Microft with high water repellency by emulating the strncture of a lotns leaf. Water rolls like mercnry from the lotus leaf, whose surface is microscopically rough and covered with a waxlike substance with low snrface tension. It was reported that Snper-Microft exhibits good water-repellent dnrability and a high wear resistance, and at the same time it possesses moisture permeability and waterproof characteristics. 

The lotus plant grows in aquatic environments. To thrive in such an environment the surface of a lotus leaf is highly water repellent. Scientists call surfaces with this property superhydrophobic. The superhydrophobic character of the lotus leaf not only allows it to float on water but also causes any water that falls on the leaf to bead up and roll off. The water drops collect dirt as they roll off, keeping the leaf clean, even in the muddy ponds and lakes where lotus plants tend to grow. Because of its self-cleaning properties, the lotus plant is considered a symbol of purity in many Eastern cultures. 

Figure 4. SEM images of naturally superhydrophobic surfaces (a, b) lotus leaf and (c, d) water strider leg (reprinted with permission from WUey Interscience [29] and Nature Publishing Group [31]).

Figure 1. SEM images of roughness structure on a lotus leaf (Nelumbo nucifera).

The comparison of the corresponding Master-PSD curves is given in Fig. 10. The characteristic cellular structures of the leaf surfaces occur as characteristic bumps at low spatial frequencies in the otherwise fractal-like PSDs. Within the spatial frequency range / = (10 , ..., 1) jm kb values of 0.2 and 0.4 were calculated for the kohlrabi and the lotus leaves, respectively. In comparison, very high Kb values > 1.0 (lotus 2.1 kohlrabi 1.5) were estimated for both samples within the spatial frequency range / = (1,..., 10) om after extrapolation of the PSD curves. This means the expected ultra-hydrophobicity of these leaves is mainly supported by sub-micrometer roughness components, even in the case of the famous micrometer-sized regular surface structures of the lotus leaf. 

Four different topographies of rough surfaces are compared in the present study a cylinder, a truncated cone, a paraboloid and a hemisphere. All of them represent ordered rough surfaces, for which the roughness features are either curved or straight, with and without sharp comers. The cylinders represent a frequently used surface, usually made by lithography [42] the paraboloids represent a shape somewhat similar to that of the protrusions on the Lotus leaf [17] the truncated cone is roughly an intermediate shape between a cylinder and a paraboloid and the hemisphere is a round form to be compared with the paraboloid. 

Surfaces of certain plants — such as the leaf of the Lotus plant — have a surface topography with two scales of roughness in the form of a base profile with peak-to-peak distances of the order of several micrometers and a superposed fine structure with peak-to-peak distances significantly below one micrometer [7-11]. Given this, the Lotus leaf follows the Cassie-Baxter state as sketched in Fig. Ic. Surfaces with... 

Superhydrophobic surfaces (water contact angles higher than 150°) can only be achieved by a combination of hydrophobicity (low surface energy materials) with appropriate surface texture. In nature one can find an array of impressive and elegant examples of superhydrophobic surfaces. For example, on a lotus leaf rain drops bounce off after impact, then entirely roil off the lotus leaf and drag along any dirt particles, without leaving residues. 

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