Robust and Eco-Friendly Superhydrophobic Starch Nanohybrid Materials with Engineered Lotus Leaf Mimetic Multiscale Hierarchical Structures

2021 ◽  
Author(s):  
Mehran Ghasemlou ◽  
Phuc H. Le ◽  
Fugen Daver ◽  
Billy J. Murdoch ◽  
Elena P. Ivanova ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Lotus Leaf ◽  
Nanohybrid Materials

Robust Superhydrophobic Carbon Nanotube Film with Lotus Leaf Mimetic Multiscale Hierarchical Structures

ACS Nano ◽  
2017 ◽  
Vol 11 (12) ◽  
pp. 12385-12391 ◽  
Author(s):  
Pengwei Wang ◽  
Tianyi Zhao ◽  
Ruixin Bian ◽  
Guangyan Wang ◽  
Huan Liu
Keyword(s):  
Carbon Nanotube ◽  
Hierarchical Structures ◽  
Lotus Leaf ◽  
Carbon Nanotube Film

scholarly journals Air Bubble Bursting Effect of Lotus Leaf

2009 ◽  
Author(s):  
Jingming Wang ◽  
Yongmei Zheng ◽  
Fu-Qiang Nie ◽  
Jin Zhai ◽  
Lei Jiang
Keyword(s):  
Leaf Surface ◽  
Water Environment ◽  
Hierarchical Structures ◽  
Underlying Mechanism ◽  
Superhydrophobic Surfaces ◽  
Micro Structure ◽  
Nano Structure ◽  
Lotus Leaf ◽  
Air Bubble ◽  
Bubble Bursting

Superhydrophobic surfaces, especially lotus leaf surface, have been largely explored due to their great importance in fundamental research and abundant potential applications. However, many efforts have been focused on investigating the superhydrophobic surfaces in air instead of in water environment, which are rather crucial to industrial separation progress. A novel air bubble bursting effect on lotus leaf surface was firstly discovered and the underlying mechanism was believed to be related to the micro/nano-hierarchical rough structures. Inspired by air bubble bursting effect on lotus leaf, a superhydrophobic “artificial lotus leaf” with similar micro/nano-hierarchical rough structures was successfully constructed by photolithography and wet etching and also achieved air bubble bursting effect. Smooth and rough silicon surface with the ordered nano-structure or patterned micro-structure were utilized to study the contribution of the micro/nano-hierarchical structures to air bubble bursting, and it was found that air bubble could burst on the superhydrophobic surfaces with micro-structure, but more time was required, while nano-structure could accelerate air bubble bursting. Moreover, the height, width, and spacing of hierarchical structures also affected air bubble bursting, and the effect of the height was more obvious. When the height of hierarchical structures was around the height of lotus papillae, the width and spacing were significant for air bubble bursting. Eventually, an original model was proposed to further evaluate the reason that the micro/nano-hierarchical rough structures had an excellent air bubble bursting effect, and its validity was theoretically demonstrated. It was believed that these findings should spark further theoretical study of some bubble-related interfacial phenomena and find its wide applications in the industrial separation process without any accessional energy and other additives, such as mineral flotation, food processing, textile dyeing, and fermentation.

Experimental Characterization of Vibration-Assisted Reverse Micro Electrical Discharge Machining (EDM) for Surface Texturing

2012 ◽  
Author(s):  
Sachin Mastud ◽  
Mayank Garg ◽  
Ramesh Singh ◽  
Johnson Samuel ◽  
Suhas Joshi
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Hierarchical Structures ◽  
Textured Surface ◽  
Fish Scale ◽  
Textured Surfaces ◽  
Process Stability ◽  
Lotus Leaf ◽  
Micro Electrical Discharge Machining ◽  
Lotus Leaves

There are several examples in nature where the biological surfaces exhibit unique functional response, such as velcro, fish scale and lotus leaves. The texture on lotus leaf exhibits super-hydrophobicity and self cleaning properties. Lotus leaf has hemispherical protrusions of 20–30 μm in diameters which are randomly distributed over the surface. This work is focused on creating similar textured surfaces on Ti6Al4V rods via a vibration assisted reverse micro Electrical Discharge Machining (R-MEDM) process. Textured surfaces containing micropillars of 40–50 μm in diameter spaced at 35 μm have been created during the process. These textured surfaces are expected to exhibit hydrophobicity and hemocompatibility. To experimentally characterize the process, a full factorial design of experiments has been conducted to analyze the effects of voltage, capacitance, amplitude and frequency of the anode (plate electrode) vibrations on the erosion rate and process stability. The process stability is expressed in terms of the percentages of the normal, open circuit and the short circuit durations in the voltage-current (VI) signature obtained during the process. It has been observed that the normal discharge durations increase with an increase in the amplitude and the frequency of the vibrations. Fabricated texture exhibits hydrophobicity and the measured contact angles in a sessile drop test with water varied between 110 and 115°. Also, the textured surface was subjected to hemotoxicity tests which yielded positive results. Based on these results, it can be seen that the machined textured surface are hydrophobic and biocompatible in nature which could potentially find applications in cardiovascular biomedical implants. In addition, this process has been used to create hierarchical structures comprising of primary and a secondary structure over it to mimic the hierarchical structures found on lotus leaves.

Water-Repellent Stability of Superhydrophobic Materials under Hydrostatic Pressure

2014 ◽  
Vol 633-634 ◽  
pp. 764-768
Author(s):  
Jian Ye Huang ◽  
Feng Hui Wang
Keyword(s):  
Hydrostatic Pressure ◽  
Superhydrophobic Surface ◽  
Hierarchical Structures ◽  
Water Repellency ◽  
Total Reflection ◽  
Wetting Transition ◽  
Water Repellent ◽  
Lotus Leaf ◽  
Stability Of Water ◽  
Air Film

Keeping the water-repellent stability of superhydrophobic surface is necessary in application. Based on the total reflection of Cassie interface and vacuum technique, the superhydrophobic stability of the lotus leaf and an artificial material was investigated. The results show that during the Cassie-Wenzel transition, primary wetting transition occurs at a certain pressure that in accordance with theoretical prediction. However, when the air film is entrapped between microstructures, stability of water-repellency was greatly enhanced, and part of the wetting transition can be recovered when the pressure was released. Due to the micro-and nanoscale hierarchical structures, the lotus leaf shows better water-repellent stability and dewetting property than the artificial superhydrophobic surface when the hydrostatic pressure was applied and released.

Relationships between hierarchical structure and properties in macromolecular systems

1987 ◽  
Vol 45 ◽  
pp. 440-443
Author(s):  
E. Baer
Keyword(s):  
Uniaxial Tension ◽  
Hierarchical Structure ◽  
Inorganic Material ◽  
Hierarchical Structures ◽  
Bone Collagen ◽  
Structure And Properties ◽  
Connective Tissues ◽  
Scale Level ◽  
Fibrous Protein ◽  
Macromolecular Systems

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.

Biomimetic materials: An introduction

1992 ◽  
Vol 50 (2) ◽  
pp. 1020-1021 ◽  
Author(s):  
M. Sarikaya ◽  
J. T. Staley ◽  
I. A. Aksay
Keyword(s):  
Self Assembly ◽  
Structural Control ◽  
Hierarchical Structures ◽  
Ceramic Composites ◽  
Advanced Materials ◽  
Length Scale ◽  
Spider Webs ◽  
Biomimetic Materials ◽  
Synthetic Materials ◽  
All Ceramic

Biomimetics is an area of research in which the analysis of structures and functions of natural materials provide a source of inspiration for design and processing concepts for novel synthetic materials. Through biomimetics, it may be possible to establish structural control on a continuous length scale, resulting in superior structures able to withstand the requirements placed upon advanced materials. It is well recognized that biological systems efficiently produce complex and hierarchical structures on the molecular, micrometer, and macro scales with unique properties, and with greater structural control than is possible with synthetic materials. The dynamism of these systems allows the collection and transport of constituents; the nucleation, configuration, and growth of new structures by self-assembly; and the repair and replacement of old and damaged components. These materials include all-organic components such as spider webs and insect cuticles (Fig. 1); inorganic-organic composites, such as seashells (Fig. 2) and bones; all-ceramic composites, such as sea urchin teeth, spines, and other skeletal units (Fig. 3); and inorganic ultrafine magnetic and semiconducting particles produced by bacteria and algae, respectively (Fig. 4).

Hierarchical structures lead to high thermoelectric performance in Cum+nPb100SbmTe100Se2m (CLAST)

2021 ◽  
Author(s):  
Siqi Wang ◽  
Yu Xiao ◽  
Yongjin Chen ◽  
Shang Peng ◽  
Dongyang Wang ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Phonon Transport ◽  
Thermoelectric Performance

Hierarchical microstructures lead to high thermoelectric performance in Cum+nPb100SbmTe100Se2m (CLAST) through synergistically optimizing carrier and phonon transport.

Sign in / Sign up

Export Citation Format

Share Document