High Adhesive Superhydrophobicity and Wetting Mechanism of Locust Wing Surface

2015 ◽  
Vol 1089 ◽  
pp. 190-193
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Tertiary Structure ◽  
Coupling Effect ◽  
Wing Surface ◽  
Microfluidic Channels ◽  
Functional Surface ◽  
Structural Element ◽  
Wing Vein ◽  
Material Element ◽  
Infrared Spectrometer ◽  
Locust Wing

The complex wettability, chemical composition and microstructure of locust wing surface were investigated by a video-based contact angle (CA) meter, a Fourier transform infrared spectrometer (FT-IR) and a scanning electron microscope (SEM). A model for hydrophobicity of wing surface was established on the basis of Cassie equation. The wetting mechanism was discussed from the perspective of biological coupling. The wing surface is a waxy layer composed mainly of long chain hydrocarbon, tallate and fatty-acid alcohol, possesses multiple-dimensional rough microstructures including primary structure (wing vein grids), secondary structure (regularly arraying micrometric pillar gibbosities), and tertiary structure (nanocorrugations). The diameter, height, and spacing of pillar gibbosity are 3.0~10.2 μm, 3.4~9.2 μm, and 7.5~18.5 μm, respectively. Locust wing surface is of high adhesive superhydrophobicity (CA 150.1~157.3°). The complex wettability of the wing surface ascribes to coupling effect of material element (waxy crystal) and structural element (hierarchical rough microstructure). Locust wing can be potentially used as a biomimetic template for design of special functional surface. This work may bring insights for preparation of micro-controllable superhydrophobic surface and no-loss microfluidic channels.

Self-Cleaning Characteristic of the Insect (Lepidoptera) Wing Surfaces

2015 ◽  
Vol 1089 ◽  
pp. 198-201
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Coupling Effect ◽  
Removal Rate ◽  
Wing Surface ◽  
Particle Removal ◽  
Structural Element ◽  
Sliding Angle ◽  
Cleaning Performance ◽  
Material Element ◽  
Infrared Spectrometer ◽  
Self Cleaning

The microstructure, hydrophobicity, adhesion and chemical composition of the butterfly and the moth wing surfaces were investigated by a scanning electron microscope (SEM), a contact angle (CA) meter, and a Fourier transform infrared spectrometer (FT-IR). Using ground calcium carbonate (heavy CaCO3) as contaminating particle, the self-cleaning performance of the wing surface was evaluated. The wing surfaces, composed of naturally hydrophobic material (chitin, protein, fat, etc.), possess complicated hierarchical micro/nanostructures. According to the large CA (149.5~156.9° for butterfly, 150.5~155.6° for moth) and small sliding angle (SA, 1~3°), the wing surface is of low adhesion and superhydrophobicity. The removal rate of contaminating particle from the wing surface is averagely 88.3% (butterfly wing) and 88.0% (moth wing). There is a good positive correlation (R2=0.8152 for butterfly, 0.8436 for moth) between particle removal rate and roughness index of the wing surface. The coupling effect of material element and structural element contributes to the outstanding superhydrophobicity and self-cleaning performance of the wing surface. The wings of Lepidoptera insect can be potentially used as templates for biomimetic preparation of intelligent interfacial material with multi-functions.

A Comparative Study on the Wettability between Butterfly and Locust Wing Surface

2015 ◽  
Vol 1089 ◽  
pp. 181-184
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Contact Angle ◽  
Coupling Effect ◽  
Wing Surface ◽  
Functional Surface ◽  
Sliding Angle ◽  
High Adhesion ◽  
Infrared Spectrometer ◽  
Ft Ir ◽  
Transport Channels ◽  
Locust Wing

The microstructure, hydrophobicity and chemical composition of the butterfly and locust wing surfaces were investigated by a scanning electron microscope (SEM), a contact angle meter and a Fourier transform infrared spectrometer (FT-IR). The hydrophobicity models were established on the basis of the Cassie equation. The wetting mechanism was comparatively discussed from the perspective of biological coupling. The butterfly and the locust wing surfaces are composed of naturally hydrophobic materials, but exhibit different complex wettability. The butterfly wing surface is of low adhesion (sliding angle 1~3°) and superhydrophobicity (contact angle 151.6~156.9°), while the locust wing surface is of extremely high adhesion (sliding angle>180°) and superhydrophobicity (contact angle 155.8~157.3°). The complex wettability of the wing surfaces ascribes to the coupling effect of hydrophobic material and rough structure. The butterfly and locust wings can be used as bio-templates for design and preparation of biomimetic functional surface, intelligent interfacial material and no-loss microfluidic transport channels.

Low Adhesive Superhydrophobicity and Self-Cleaning Property of Moth Wing

2015 ◽  
Vol 1089 ◽  
pp. 194-197
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Coupling Effect ◽  
Removal Rate ◽  
The Self ◽  
Wing Surface ◽  
Particle Removal ◽  
Structural Element ◽  
Sliding Angle ◽  
Material Element ◽  
Infrared Spectrometer ◽  
Self Cleaning

The microstructure, hydrophobicity, adhesion, and chemical composition of moth wing surfaces were investigated by a scanning electron microscope (SEM), a contact angle (CA) meter, and a Fourier transform infrared spectrometer (FT-IR). Using ground calcium carbonate (heavy CaCO3) as contaminating particle, the self-cleaning performance of wing surface was evaluated. The self-cleaning mechanism was discussed from the perspective of biological coupling. The wing surfaces, composed of naturally hydrophobic material (chitin, protein, fat, etc.), possess complicated hierarchical micro/nano structures. According to the large CA (138.9~158.4°) and small sliding angle (SA, 1~3°) of water droplet, moth wing surface is of low adhesion and high hydrophobicity. The removal rate of contaminating particle from wing surface is averagely 83.8%. There is a good positive correlation (r=0.81) between particle removal rate and roughness index of wing surface. The coupling effect of material element and structural element leads to the remarkable hydrophobicity and self-cleaning property of the wing surface. Moth wing can be potentially used as a template for biomimetic design of functional material with complex wettability. This work may offer interesting inspirations for preparation of smart interfacial material.

Water/Methanol-Repellency and Wetting Mechanism of Moth Wing Surface

2015 ◽  
Vol 723 ◽  
pp. 948-951
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Chemical Composition ◽  
Coupling Effect ◽  
Methanol Solution ◽  
Wing Surface ◽  
Functional Surface ◽  
Bionic Design ◽  
Infrared Spectrometer ◽  
Ft Ir ◽  
Scanning Electron ◽  
Hydrophobic Material

The water-and methanol-repellent properties of moth wing surfaces were determined by a contact angle (CA) meter, the chemical composition and microstructures of moth wing surfaces were investigated by a Fourier transform infrared spectrometer (FT-IR) and a scanning electron microscope (SEM). The wing surface is composed of naturally hydrophobic material and possesses hierarchical rough structures. The wing surface exhibits high repellency against water (CA 139.2~155.6°) and methanol solution. The critical concentrations for wetting and spreading-wetting of methanol solution on the wing surfaces are 60% and 80%, respectively. The complex wettability of the wing surface ascribes to the coupling effect of chemical composition and micro/nanostructure. Moth wing can be used as a template for bionic design of special functional surface.

A Comparison of the Complex Wettability between Locust and Moth Wing

2015 ◽  
Vol 1095 ◽  
pp. 593-597
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Contact Angle ◽  
Wing Surface ◽  
Baxter Equation ◽  
Structural Element ◽  
Sliding Angle ◽  
High Adhesion ◽  
Material Element ◽  
Infrared Spectrometer ◽  
Transport Channels ◽  
Functional Interface

The microstructure, hydrophobicity and chemical composition of the locust and moth wing surfaces were investigated by a scanning electron microscope (SEM), a contact angle meter and a Fourier transform infrared spectrometer (FT-IR). The hydrophobicity models were established on the basis of the Cassie-Baxter equation. The locust and moth wing surfaces are composed of naturally hydrophobic materials, but exhibit different complex wettability. The locust wing surface is of extremely high adhesion (sliding angle>180°) and superhydrophobicity (contact angle 151.5~157.3°), while the moth wing surface is of low adhesion (sliding angle 1~3°) and superhydrophobicity (contact angle 150.5~155.6°). The complex wettability of the wing surfaces ascribes to the cooperative effect of material element and structural element. The locust and moth wings can be potentially used as biomimetic templates for design and preparation of novel functional interface and no-loss microfluidic transport channels.

Effects of Nano Silver Film on the Hydrophobicity of Moth Wing

2015 ◽  
Vol 1095 ◽  
pp. 608-611
Author(s):  
Yan Fang ◽  
Gang Sun
Keyword(s):  
Silver Film ◽  
Tertiary Structure ◽  
Wing Surface ◽  
Optical Contact ◽  
Silver Films ◽  
Biological Coupling ◽  
Infrared Spectrometer ◽  
Ft Ir ◽  
Micro Morphology ◽  
Hydrophobic Material

The microstructure, superhydrophobicity and chemical composition of the moth wing surface were investigated by a scanning electron microscope (SEM), an optical contact angle (CA) meter and a Fourier transform infrared spectrometer (FT-IR). nanosilver film was coated on the wing surface by vacuum evaporation. The wetting mechanism was discussed from the perspective of biological coupling. The moth wing surface, composed of naturally hydrophobic material, is of high hydrophobicity (CA 143~156°) and exhibits complicated hierarchical micro-morphology including primary structure, secondary structure and tertiary structure. The cooperation of hydrophobic material and rough micro-morphology leads to the high hydrophobicity of the wing surface. The wing surfaces coated with 50~1000 nm silver films are still hydrophobic (CA > 110°). The multiple-dimensional rough structure of the wing surface results in the transition of metal silver from hydrophilic to hydrophobic. The moth wing can serve as a bio-template for design and preparation of micro-controllable superhydrophobic surface.

Preparation and Characterization of Hybrid Graphene-ZnS Nanoparticles

2010 ◽  
Vol 663-665 ◽  
pp. 894-897
Author(s):  
Hua Huang ◽  
Hai Hu Yu ◽  
Ling De Zhou ◽  
Er Dan Gu ◽  
De Sheng Jiang
Keyword(s):  
Coupling Effect ◽  
Zinc Acetate Dihydrate ◽  
Graphene Sheets ◽  
Acetate Dihydrate ◽  
Zns Nanoparticles ◽  
Transmission Electron ◽  
Infrared Spectrometer ◽  
One Step ◽  
Average Size

Hybrid Graphene-ZnS nanopaticles (G-ZnS NPs) were prepared by using a solvothermal method. A dispersion of graphite oxide (GO) and zinc acetate dihydrate (Zn(CH3COO)2.2H2O) in dimethl sulfoxide (DMSO) reacted at 180 °C for 12 h in a Telfon-lined stainless steel autoclave. In the reaction, DMSO serves as a sulphide source as well as a reducing agent, resulting formation of the hybrid G-ZnS NPs in one-step. Hybrid G-ZnS NPs were characterized by using a powder X-ray diffractometer, a Fourier-transform infrared spectrometer, a transmission electron microscope, a UV-vis spectrophotometer and a fluorescence spectrophotometer, respectively. In the FTIR spectra, the GO related stretching bands of C-O and carboxyl groups are not observed in the spectra of G-ZnS, suggesting that the GO sheets were reduced to graphene sheets. In the TEM images, it is observed that the ZnS nanoparticles with an average size of 23 nm are attached onto the graphene sheets. The UV-vis absorption spectrum of the G-ZnS NPs dispersed in ethanol has an absorption peak of G at 261 nm and a weak shoulder of ZnS NPs around 320 nm. The broadening and weakening of the peak of ZnS NPs at 320 nm arises from the interparticle coupling effect. Under excitation at 225 nm, a peak around 386 nm and other weaker bands appear in the fluorescence spectrum of the G-ZnS. The band at 386 nm is attributed to zinc vacancies.

scholarly journals Quaternary structure independent folding of voltage-gated ion channel pore domain subunits

2021 ◽  
Author(s):  
Cristina Arrigoni ◽  
Marco Lolicato ◽  
David Shaya ◽  
Ahmed Rohaim ◽  
Felix Findeisen ◽  
...  
Keyword(s):  
Ion Channel ◽  
Tertiary Structure ◽  
Quaternary Structure ◽  
Transmembrane Helix ◽  
Full Length ◽  
Structural Element ◽  
Voltage Gated ◽  
Evolutionary Origins ◽  
Ion Conducting ◽  
Pore Domain

Every voltage-gated ion channel (VGIC) superfamily member has an ion conducting pore consisting of four pore domain (PD) subunits that are each built from a common plan comprising an antiparallel transmembrane helix pair, a short, obliquely positioned helix (the pore helix), and selectivity filter. The extent to which this structure, the VGIC-PD fold, relies on the extensive quaternary interactions observed in PD assemblies is unclear. Here, we present crystal structures of three bacterial voltage-gated sodium channel (BacNaV) pores that adopt a surprising set of non canonical quaternary structures and yet maintain the native tertiary structure of the PD monomer. This context-independent structural robustness demonstrates that the VGIC-PD fold, the fundamental VGIC structural building block, can adopt its native-like tertiary fold independent of native quaternary interactions. In line with this observation, we find that the VGIC PD fold is not only present throughout the VGIC superfamily and other channel classes but has homologs in diverse transmembrane and soluble proteins. Characterization of the structures of two synthetic Fabs (sFabs) that recognize the VGIC PD fold shows that such sFabs can bind purified full-length channels and indicates that non-canonical quaternary PD assemblies can occur in the context of complete VGICs. Together, our data demonstrate that the VGIC-PD structure can fold independently of higher order assembly interactions and suggest that full length VGIC PDs can access previously unknown non-canonical quaternary states. These PD properties have deep implications for understanding how the complex quaternary architectures of VGIC superfamily members are achieved and point to possible evolutionary origins of this fundamental VGIC structural element.

Complex Wettability and Self-Cleaning Performance of Butterfly Wing Surface

2015 ◽  
Vol 723 ◽  
pp. 943-947 ◽  
Author(s):  
Yan Fang ◽  
Gang Sun
Keyword(s):  
Removal Rate ◽  
Average Rate ◽  
Contact Angles ◽  
Wing Surface ◽  
Butterfly Wing ◽  
Cleaning Performance ◽  
Infrared Spectrometer ◽  
Self Cleaning ◽  
Pollution Removal ◽  
Special Complex

The microstructure, hydrophobicity and chemical composition of butterfly wing surfaces were investigated by a scanning electron microscope (SEM), a video-based contact angle meter, and a Fourier transform infrared spectrometer (FT-IR). Using CaCO3 particle as simulated pollutant, the self-cleaning performance of the wing surface was measured. The wing surfaces possess complicated micro/nanostructures. According to the large contact angles (140.2~156.9°) and small sliding angles (1~3°) of water droplet, the butterfly wing surface is of high hydrophobicity and low adhesion. The average rate of CaCO3 pollution removal from the wing surface is as high as 86.2%. There is a good positive correlation (r=0.89) between pollution removal rate and roughness index of the wing surface. The coupling effects of hydrophobic material and rough microstructure contribute to the special complex wettability and remarkable self-cleaning property of the wing surface. Butterfly wing can be used as a template for design of superhydrophobic surface and self-cleaning material. This work may offer inspirations for biomimetic fabrication of novel interfacial material with multi-functions.

scholarly journals Surface To Surface Map Algorithm For Protein - Small Molecule Matching

2013 ◽  
pp. 7-10
Author(s):  
Neha Gupta ◽  
Megha Bajaj
Keyword(s):  
Active Sites ◽  
Tertiary Structure ◽  
Sequence Similarity ◽  
Surface Matching ◽  
Functional Surface ◽  
3 Dimensional ◽  
Shaped Surface ◽  
Ligand Binding Sites ◽  
Related Proteins ◽  
Initial Results

Current methods for protein analysis are based on either sequence similarity or comparison of overall tertiary structure. These conserved primary sequences or 3-dimensional structures may imply similar functional characteristics. However, substrate or ligand binding sites usually reside on or near protein surface, so, similarly shaped surface regions could imply similar functions. Our current work includes development of an algorithm that would allow surface matching over specific regions on related proteins with an output equal to the match percentage between two proteins. Initial results indicate that we can successfully match a family of related active sites, and find their similarly shaped surface regions. This method of surface analysis could be extended to help us understand functional surface relationship between the proteins within which there is no relationship in sequence or overall structure.

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