scholarly journals Bioinspired Nanoscale Hierarchical Pillars for Extreme Superhydrophobicity and Wide Angular Transmittance

2022 ◽  
Author(s):  
Cheonji Lee ◽  
Seungmook Ji ◽  
Sunjong Oh ◽  
Seungchul Park ◽  
Yungdo Jung ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Structured Surfaces ◽  
Living Organisms ◽  
Dual Functions

Hierarchical structures in nature provide unique functions for living organisms that can inspire technology. Nanoscale hierarchical structured surfaces are essential to realize the dual functions of non-wetting and transparency for...

scholarly journals Self-Organization of Motor-Propelled Cytoskeletal Filaments at Topographically Defined Borders

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Alf Månsson ◽  
Richard Bunk ◽  
Mark Sundberg ◽  
Lars Montelius
Keyword(s):  
Molecular Motor ◽  
Direct Consequence ◽  
Self Organization ◽  
Test Model ◽  
Structured Surfaces ◽  
Microstructured Surfaces ◽  
Living Organisms ◽  
Edge Tracing ◽  
Motor Density

Self-organization phenomena are of critical importance in living organisms and of great interest to exploit in nanotechnology. Here we describe in vitro self-organization of molecular motor-propelled actin filaments, manifested as a tendency of the filaments to accumulate in high density close to topographically defined edges on nano- and microstructured surfaces. We hypothesized that this “edge-tracing” effect either (1) results from increased motor density along the guiding edges or (2) is a direct consequence of the asymmetric constraints on stochastic changes in filament sliding direction imposed by the edges. The latter hypothesis is well captured by a model explicitly defining the constraints of motility on structured surfaces in combination with Monte-Carlo simulations [cf. Nitta et al. (2006)] of filament sliding. In support of hypothesis 2 we found that the model reproduced the edge tracing effect without the need to assume increased motor density at the edges. We then used model simulations to elucidate mechanistic details. The results are discussed in relation to nanotechnological applications and future experiments to test model predictions.

scholarly journals Tunable Hierarchical Nanostructures on Micro-Conical Arrays of Laser Textured TC4 Substrate by Hydrothermal Treatment for Enhanced Anti-Icing Property

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 450
Author(s):  
Mengyao Liu ◽  
Rui Zhou ◽  
Zhekun Chen ◽  
Huangping Yan ◽  
Jingqin Cui ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Hydrothermal Treatment ◽  
Hierarchical Structures ◽  
Contact Angles ◽  
Hydrothermal Temperature ◽  
Hierarchical Nanostructures ◽  
Structured Surfaces ◽  
Patterned Surface ◽  
Nanosecond Pulsed Laser ◽  
Tio2 Nanostructures

In this work, an anti-icing structured surface was fabricated by combining laser ablation with hydrothermal treatment. A micro-patterned surface on a Ti alloy (TC4) substrate was easily fabricated by a highly effective nanosecond pulsed laser ablation. It was observed that titania (TiO2) nanostructures were formed by hydrothermal treatment in aqueous alkali on the laser ablated TC4 substrate to obtain the micro/nano-hierarchical structures. The growth mechanism of the tunable nanoarrays was discussed by the adjustment of hydrothermal temperature. The as-prepared samples exhibited excellent superhydrophobicity with contact angles greater than 160°. It was found that optimized hydrothermal treatment on laser-processed TC4 substrates could further enhance surface anti-icing property. The results showed that the delay time (DT) had been extended by achieving over 90 min for the water droplets to freeze on the as-prepared structured surfaces, providing great potential in various anti-icing applications.

scholarly journals Hierarchical structures of cactus spines that aid in the directional movement of dew droplets

2016 ◽  
Vol 374 (2073) ◽  
pp. 20160110 ◽  
Author(s):  
F. T. Malik ◽  
R. M. Clement ◽  
D. T. Gethin ◽  
M. Kiernan ◽  
T. Goral ◽  
...  
Keyword(s):  
Small Area ◽  
Hierarchical Structures ◽  
Time Lapse ◽  
Fluorescent Nanoparticles ◽  
Vascular Bundles ◽  
Resonance Imaging ◽  
Sem Images ◽  
Structured Surfaces ◽  
The Core ◽  
Directional Movement

Three species of cactus whose spines act as dew harvesters were chosen for this study: Copiapoa cinerea var. haseltoniana , Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa and compared with Ferocactus wislizenii whose spines do not perform as dew harvesters. Time-lapse snapshots of C. cinerea showed movement of dew droplets from spine tips to their base, even against gravity. Spines emanating from one of the areoles of C. cinerea were submerged in water laced with fluorescent nanoparticles and this particular areole with its spines and a small area of stem was removed and imaged. These images clearly showed that fluorescent water had moved into the stem of the plant. Lines of vascular bundles radiating inwards from the surface areoles (from where the spines emanate) to the core of the stem were detected using magnetic resonance imaging, with the exception of F. wislizenii that does not harvest dew on its spines. Spine microstructures were examined using SEM images and surface roughness measurements ( R a and R z ) taken of the spines of C. cinerea . It was found that a roughness gradient created by tapered microgrooves existed that could potentially direct surface water from a spine tip to its base. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’.

Redox Reactions in Lipid Membranes as a Model for Primordial Energy-Conserving Systems

1997 ◽  
Vol 161 ◽  
pp. 437-442
Author(s):  
Salvatore Di Bernardo ◽  
Romana Fato ◽  
Giorgio Lenaz
Keyword(s):  
Experimental Evidence ◽  
Lipid Membranes ◽  
Energy Supply ◽  
Redox Reactions ◽  
Living Systems ◽  
Asymmetric Distribution ◽  
Conservation Of Energy ◽  
Asymmetrical Distribution ◽  
Energy Conserving ◽  
Living Organisms

AbstractOne of the peculiar aspects of living systems is the production and conservation of energy. This aspect is provided by specialized organelles, such as the mitochondria and chloroplasts, in developed living organisms. In primordial systems lacking specialized enzymatic complexes the energy supply was probably bound to the generation and maintenance of an asymmetric distribution of charged molecules in compartmentalized systems. On the basis of experimental evidence, we suggest that lipophilic quinones were involved in the generation of this asymmetrical distribution of charges through vectorial redox reactions across lipid membranes.

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.

Neutral Lipids of Oats Fruit (Avena Sativa L.)

2020 ◽  
Vol 9 (4) ◽  
pp. 40-43
Author(s):  
N. K. Yuldasheva ◽  
S. D. Gusakova ◽  
D. Kh. Nurullaeva ◽  
N. T. Farmanova ◽  
R. P. Zakirova ◽  
...  
Keyword(s):  
Avena Sativa ◽  
Neutral Lipids ◽  
The Body ◽  
Biologically Active ◽  
Absorption Bands ◽  
Vital Functions ◽  
The Republic ◽  
Living Organisms ◽  
Main Components ◽  
Active Substances

Introduction. Lipids are a widespread group of biologically active substances in nature, making up the bulk of the organic substances of all living organisms. They accumulate in plants in seeds, as well as in fruits and perform a number of vital functions: they are the main components of cell membranes and the energy reserve for the body.Aim. Study of neutral lipids of sown oats (Avena sativa L.).Materials and methods. The objects of the study were fruits (grains) of oats of the sown variety "Tashkent 1," harvested in the Republic of Uzbekistan. Results and discussions. Neutral lipids of oat grains have been found to contain 13 fatty acids with a predominance of the sum of oleic, linolenic and linoleic acids. The total degree of unsaturation was almost 78%. Absorption bands characteristic of these substances were observed in the IR spectrum of MEGC.Conclusion. According to the results of the NL analysis, oat grains consisted of triacylglycerides and free LCDs, which were accompanied by hydrocarbons, phytosterols, triterpenoids and tocopherols.

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