scholarly journals Adhesion Performance in the Eggs of the Philippine Leaf Insect Phyllium philippinicum (Phasmatodea: Phylliidae)

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 400 ◽  
Author(s):  
Thies H. Büscher ◽  
Elise Quigley ◽  
Stanislav N. Gorb
Keyword(s):  
Surface Chemistry ◽  
Surface Profile ◽  
Water Contact ◽  
Plant Seeds ◽  
Attachment Strength ◽  
Influence Of Water ◽  
Water Adhesion ◽  
Attachment Mechanism ◽  
Taxonomic Studies ◽  
Microscopy Techniques

Leaf insects (Phasmatodea: Phylliidae) exhibit perfect crypsis imitating leaves. Although the special appearance of the eggs of the species Phyllium philippinicum, which imitate plant seeds, has received attention in different taxonomic studies, the attachment capability of the eggs remains rather anecdotical. We herein elucidate the specialized attachment mechanism of the eggs of this species and provide the first experimental approach to systematically characterize the functional properties of their adhesion by using different microscopy techniques and attachment force measurements on substrates with differing degrees of roughness and surface chemistry, as well as repetitive attachment/detachment cycles while under the influence of water contact. We found that a combination of folded exochorionic structures (pinnae) and a film of adhesive secretion contribute to attachment, which both respond to water. Adhesion is initiated by the glue, which becomes fluid through hydration, enabling adaption to the surface profile. Hierarchically structured pinnae support the spreading of the glue and reinforcement of the film. This combination aids the egg’s surface in adapting to the surface roughness, yet the attachment strength is additionally influenced by the egg’s surface chemistry, favoring hydrophilic substrates. Repetitive detachment and water-mediated adhesion can optimize the location of the egg to ensure suitable environmental conditions for embryonic development. Furthermore, this repeatable and water-controlled adhesion mechanism can stimulate further research for biomimeticists, ecologists and conservationalists.

Influence of water adhesion of superhydrophobic surfaces on their anti-corrosive behavior

2018 ◽  
Vol 347 ◽  
pp. 38-45 ◽  
Author(s):  
Mengke Cui ◽  
Yongqian Shen ◽  
Haifeng Tian ◽  
Yaoxia Yang ◽  
Hua Feng ◽  
...  
Keyword(s):  
Superhydrophobic Surfaces ◽  
Influence Of Water ◽  
Water Adhesion

The Study on Surface Chemistry of Nanoporous Black Si Layers

2011 ◽  
Vol 79 ◽  
pp. 304-308
Author(s):  
Wang Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Chemistry ◽  
Point Defects ◽  
High Density ◽  
Nanometer Scale ◽  
Transmission Electron ◽  
One Step ◽  
Amorphous Si ◽  
Microscopy Techniques

We reported our detailed investigation of the microstructure and surface chemistry of nanoporous black Si layers using transmission electron microscopy techniques such as HRTEM, EDS, and EELS. We found that a one-step nanoparticle-catalyzed liquid etch creates deep conical nanovoids. The cones provide the density-graded surface that suppresses reflection. The surface of the as-etched nanoporous black Si is an amorphous Si suboxide (SiOx) produced by the strongly oxidizing nanocatalyzed etch. The c-Si/suboxide interface is rough at the nanometer scale and contains a high density of point defects.

scholarly journals Interaction of Nanodiamonds with Water: Impact of Surface Chemistry on Hydrophilicity, Aggregation and Electrical Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2740
Author(s):  
Pietro Aprà ◽  
Lorenzo Mino ◽  
Alfio Battiato ◽  
Paolo Olivero ◽  
Sofia Sturari ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Surface Chemistry ◽  
Water Adsorption ◽  
Electrical Conductance ◽  
Depth Information ◽  
Thermal Processes ◽  
Water Impact ◽  
Temperature Dependent ◽  
Research Fields ◽  
Influence Of Water

In recent decades, nanodiamonds (NDs) have earned increasing interest in a wide variety of research fields, thanks to their excellent mechanical, chemical, and optical properties, together with the possibility of easily tuning their surface chemistry for the desired purpose. According to the application context, it is essential to acquire an extensive understanding of their interaction with water in terms of hydrophilicity, environmental adsorption, stability in solution, and impact on electrical properties. In this paper, we report on a systematic study of the effects of reducing and oxidizing thermal processes on ND surface water adsorption. Both detonation and milled NDs were analyzed by combining different techniques. Temperature-dependent infrared spectroscopy was employed to study ND surface chemistry and water adsorption, while dynamic light scattering allowed the evaluation of their behavior in solution. The influence of water adsorption on their electrical properties was also investigated and correlated with structural and optical information obtained via Raman/photoluminescence spectroscopy. In general, higher oxygen-containing surfaces exhibited higher hydrophilicity, better stability in solution, and higher electrical conduction, although for the latter the surface graphitic contribution was also crucial. Our results provide in-depth information on the hydrophilicity of NDs in relation to their surface chemical and physical properties, by also evaluating the impacts on their aggregation and electrical conductance.

Super-Hydrophobic Film Fabricated on Copper with Electro-Deposition Method and its Corrosion Resistance

2013 ◽  
Vol 803 ◽  
pp. 278-281 ◽  
Author(s):  
Peng Wang ◽  
Dun Zhang ◽  
Peng Ju
Keyword(s):  
Copper Film ◽  
Electrochemical Measurement ◽  
Copper Surface ◽  
Metallic Surface ◽  
Hydrophobic Property ◽  
Time Saving ◽  
Water Contact ◽  
Tetradecanoic Acid ◽  
Electro Deposition ◽  
Water Adhesion

Copper film with rough structure is prepared on metal surface via electro-deposition. After modification of tetradecanoic acid, copper film presents super-hydrophobic property with water contact angle of 151.1°, which could be attributed to the rough structure by trapping air. The adhesion test shows that the modified copper surface has low apparent water adhesion to the suspending droplet. Electrochemical measurement proves that super-hydrophobic film can inhibit corrosion of copper effectively. The method proposed in this paper is time-saving and facile to operate, and it offers a promising technique to prepare metallic surface with super-hydrophobic property.

Influence of Water on Fatigue-Failure Location and Surface Alteration During Rolling-Contact Lubrication

1969 ◽  
Vol 91 (2) ◽  
pp. 301-307 ◽  
Author(s):  
P. Schatzberg ◽  
I. M. Felsen
Keyword(s):  
Light Microscopy ◽  
Compressive Stress ◽  
Fatigue Failure ◽  
Surface Profile ◽  
Rolling Contact ◽  
Influence Of Water ◽  
Surface Alteration ◽  
Failure Location ◽  
Fatigue Failures ◽  
Bearing Ball

The influence of dissolved water in the lubricant on fatigue-failure location and surface alteration was determined from experiments conducted with a planetary four-ball machine in the range of 925 to 1300 ksi maximum Hertz compressive stress. The distribution of fatigue spalls on the bearing ball surfaces was influenced by small amounts of water in the hydrocarbon lubricant. In the presence of 0.01 precent water an increase in fatigue-failures occurred on the chemically more reactive portion of the bearing balls. An increase in wear during rolling contact was observed due to the presence of water. This was demonstrated by weight determinations, surface profile measurements and light microscopy.

The Influence of Water Contact Angle on the Colonization of Diatoms (Navicula sp and Pinnularia sp) and Ulva Spores (Pertusa)

2013 ◽  
Vol 562-565 ◽  
pp. 1229-1233
Author(s):  
Jin Wei Zhang ◽  
Cun Guo Lin ◽  
Li Wang ◽  
Ji Yong Zheng ◽  
Feng Ling Xu
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Adhesive Force ◽  
Self Assembled Monolayers ◽  
Use Of Self ◽  
Water Contact ◽  
Force Increase ◽  
Assembled Monolayers ◽  
Influence Of Water ◽  
Proportional Relationship

The surface with different water contact angle (θAW) was prepared through the use of self-assembled monolayers (SAMs) and the effect of water contact angle on the colonization of diatoms (Naviculasp andPinnulariasp) andUlvaspores (Pertusa) was researched in an optional environment. Results revealed that the statistical adhesion density of colonized diatoms have a reciprocal-proportional relationship with θAW, and the adhesive force increase with the increase of θAW. However, it was the other way round forUlvaspores. Different with previous primary adhesion study, it also was revealed that diatoms have selectivity in colonization stage. All of these must due to their different reproduce (or grow) mode and extracellular polymers (EPS) composition.

scholarly journals The Direct Cause of Amplified Wettability: Roughness or Surface Chemistry?

2021 ◽  
Vol 5 (8) ◽  
pp. 213
Author(s):  
Emmanuel E. Ubuo ◽  
Inimfon A. Udoetok ◽  
Andrew T. Tyowua ◽  
Ifiok O. Ekwere ◽  
Hamza S. Al-Shehri
Keyword(s):  
Surface Chemistry ◽  
Solid Material ◽  
Contact Angles ◽  
Gradual Change ◽  
Water Contact ◽  
Drop Shape ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Analysis System ◽  
Glass Surfaces

Higher contact angles or amplified wettability observed on surfaces of rough solid materials are typically expressed as a function of a physical dimension (roughness factor). Herein, we present a simple experimental approach that demonstrates that roughness may only magnify the inherent surface chemistry that seems to have direct influence on surface wettability. We investigate gradual change in surface chemistry (hydrophobisation) of rough and smooth glass surfaces, from a very low concentration (10−7 M) of dichlorodimethylsilane, DCDMS through various intermediate hydrophilic/hydrophobic states to when the surfaces are maximally hydrophobised with DCDMS at 0.1 M. The wettability of the modified glasses was studied by water contact angle measurements using drop shape analysis system (DSA). The data obtained indicate a deviation from Wenzel model, with the functionalized rough glass surfaces showing higher reactivity towards DCDMS when compared to the smooth glass surfaces, indicating that the two surfaces are not chemically identical. Our study reveals that just like transforming a solid material to powder, a well-divided glass (rough) surface may not only exhibit a greater surface area than the smooth counterpart as rightly predicted by the Wenzel model, but seems to be bloated with functional groups (–OH or –CH3) that can amplify surface interaction when such functional species dominate the solid surface.

Hydrophobic Waxes in Ivory Nuts Affect Surface Modification by Atmospheric Air Plasma Jet

2021 ◽  
Vol 11 (4) ◽  
pp. 12227-12237
Author(s):  
Yuri Ferreira da Silva ◽  
Renata Nunes Oliveira ◽  
Renata Antoun Simao
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Surface Chemistry ◽  
Plasma Treatment ◽  
Water Contact Angle ◽  
Plasma Jet ◽  
Raman Imaging ◽  
Air Plasma ◽  
Water Contact ◽  
Atmospheric Air

Ivory nuts, bioproducts from South American palms, possess a hard, water-insoluble, and microporous endosperm with a strong resemblance to elephant ivory. The nuts sustainable appeal made them popular as eco-friendly substitutes to ivory and, more recently, microbeads. However, their hygroscopicity and mannan composition impart susceptibility to deterioration by microbes and insects. Cold plasma treatment has been widely investigated as a clean and cost-effective procedure for seed disinfection and surface modification. Hence, in this work, ivory nut endosperm was treated by an air plasma jet to modify wettability. Plasma treated samples were characterized by the water contact angle, AFM, and Raman imaging. Water contact angle results presented an increase from (31.5 ± 8.7)º to (78.9 ± 5.4)º, demonstrating surface hydrophobization. This result was attributed to the modification of surface chemistry by migration and repolymerization of extractives promoted by plasma treatment. AFM results evidenced the formation of a heterogeneous layer containing lamellar features similar to plant epicuticular waxes. Besides, principal component analysis of Raman imaging results highlighted spectral contributions from wax, xylan, mannan, and lignin. These results demonstrate that atmospheric air plasma jets can be employed for ivory nut hydrophobization with no need for additional precursors, altering surface chemistry by crosslinking endosperm native substances.

scholarly journals Surface Chemistry of Halloysite Nanotubes. As investigated by adsorption reactions and imaging analysis

2021 ◽  
Author(s):  
◽  
Nia B. Gray-Wannell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Chemistry ◽  
Clay Minerals ◽  
External Surface ◽  
Halloysite Nanotubes ◽  
Interlayer Water ◽  
Adsorption Sites ◽  
Transmission Electron ◽  
Microscopy Techniques

Interest in halloysite clay minerals has increased steadily over the last 20+ years, in part, due to their nanotubular shape and size, high aspect ratio and potential technological applications (Churchman et al., 2016). Throughout this thesis the surface chemistry of halloysite nanotubes is investigated by employing several analytical and advanced microscopy techniques to obtain a greater understanding of their internal and external surface features and surface adsorption reactions. This multifaceted analysis approach investigates a range of tubular halloysites of two morphologies, cylindrical and polygonal prismatic, where comparison of the two forms a framework for the presentation and discussion of the results. The results presented in Chapter 3 demonstrate the phosphate adsorption capacity of halloysite nanotubes is influenced by pH and maximum adsorptions of 1.3 mg/g and 0.5 mg/g were obtained for the cylindrical and polygonal prismatic morphologies respectively. Use of advanced microscopy techniques in Chapter 4 showed the external surface of the polygonal prismatic nanotubes have multiple steps and edges, which may act as additional adsorption sites, as has been shown for other clay minerals (Siretanu et al., 2016). In addition, use of cross-section transmission electron microscopy provided evidence of the link between the two morphologies, where the cylindrical nanotubes appear to be the template from which the larger polygonal prismatic nanotubes grow, as previously postulated by Hillier et al. (2016). In further novel work (Chapter 5), gold nanotags have been functionalised with a variety of anionic and neutral terminated linkers and used as nanoscale probes to study adsorption to the surface of halloysite nanotubes Here, transmission electron microscopy proved that the adsorption occurred primarily on the nanotube inner lumen and edges. The final technical chapter, Chapter 6, focuses on the structure and dynamics of interlayer water in halloysite through the use of neutron scattering techniques, where the initial results demonstrated that the interlayer water appears to move via both rotations and translations within the interlayer. The research presented ascertains that the surfaces of the halloysite nanotubes are more complex than often depicted for technological applications and that the specific tubular morphology is important in the functionality and behaviour of the nanotubes. This fundamental work contributes towards optimisation of halloysite nanotubes for technological applications.

scholarly journals Effect of Substratum Surface Chemistry and Surface Energy on Attachment of Marine Bacteria and Algal Spores

2004 ◽  
Vol 70 (7) ◽  
pp. 4151-4157 ◽  
Author(s):  
Linnea K. Ista ◽  
Maureen E. Callow ◽  
John A. Finlay ◽  
Sarah E. Coleman ◽  
Aleece C. Nolasco ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Contact Angles ◽  
Complex Model ◽  
Model Organisms ◽  
Water Contact ◽  
Cobetia Marina ◽  
Glass Slides ◽  
Assembled Monolayers ◽  
Enteromorpha Linza ◽  
State Models

ABSTRACT Two series of self-assembled monolayers (SAMs) of ω-substituted alkanethiolates on gold were used to systematically examine the effects of varying substratum surface chemistry and energy on the attachment of two model organisms of interest to the study of marine biofouling, the bacterium Cobetia marina (formerly Halomonas marina) and zoospores of the alga Ulva linza (formerly Enteromorpha linza). SAMs were formed on gold-coated glass slides from solutions containing mixtures of methyl- and carboxylic acid-terminated alkanethiols and mixtures of methyl- and hydroxyl-terminated alkanethiols. C. marina attached in increasing numbers to SAMs with decreasing advancing water contact angles (θAW), in accordance with equation-of-state models of colloidal attachment. Previous studies of Ulva zoospore attachment to a series of mixed methyl- and hydroxyl-terminated SAMs showed a similar correlation between substratum θAW and zoospore attachment. When the hydrophilic component of the SAMs was changed to carboxylate, however, the profile of attachment of Ulva was significantly different, suggesting that a more complex model of interfacial energetics is required.

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