Contact Angle of Nepenthes alata Slippery Zone: Results from Measurement and Model Analysis

2021 ◽  
pp. 1-7
Author(s):  
Lixin Wang ◽  
Pan Pan ◽  
Shixing Yan ◽  
Shiyun Dong
Keyword(s):  
Contact Angle ◽  
Hierarchical Structures ◽  
Model Analysis ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Structure Characteristic ◽  
Baxter Equation ◽  
Measured Contact Angle ◽  
The Relationship ◽  
Contact Angle Analysis

The slippery zone of Nepenthes alata depends on its highly evolved morphology and structure to show remarkable superhydrophobicity, which has gradually become a biomimetic prototype for developing superhydrophobic materials. However, the mechanism governing this phenomenon has not been fully revealed through model analysis. In this paper, the superhydrophobicity of slippery zone is studied by contact angle measurement, morphology/structure examination and model analysis. The slippery zone causes ultrapure water droplet to produce a considerably high contact angle (155.11–158.30°), and has a micro-nano scale hierarchical structures consisting of lunate cells and wax coverings. According to the Cassie-Baxter equation and a self-defined infiltration coefficient, a model was established to analyze the effect of structure characteristic on the contact angle. Analysis result showed that the calculated contact angle (154.67–159.49°) was highly consistent with the measured contact angle, indicating that the established model can quantitatively characterize the relationship between the contact angle and the structure characteristic. Our study provides some evidences to further reveal the superhydrophobic mechanism of Nepenthes alata slippery zone, as well as inspires the biomimetic development of superhydrophobic surfaces.

SYNTHESIS AND CHARACTERIZATION OF SUPERHYDROPHOBIC ZnO HIERARCHICAL STRUCTURES

NANO ◽  
2011 ◽  
Vol 06 (03) ◽  
pp. 265-269 ◽  
Author(s):  
QUNBING ZHANG ◽  
SHIHE CAO ◽  
JUN WANG
Keyword(s):  
Contact Angle ◽  
Hydrothermal Process ◽  
Hierarchical Structures ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zno Films ◽  
Water Contact ◽  
Simple Method ◽  
Microscopy Images

ZnO films with well-aligned hierarchical structures have been successfully synthesized at moderate temperatures using a simple catalyst-free hydrothermal process. The synthesized ZnO films are found to be single-phase, with a hexagonal wurtzite-type structure. Scanning electron microscopy images show that the well-aligned hierarchical structures are assembled with interlaced parallel sheets grown on the (400) silica surface. The water contact angle measurement indicates that the water on the films has a contact angle of about 156.3°. This clearly demonstrates that the ZnO films synthesized by this simple method have superhydrophobic properties and may be important for applications in self-cleaning surfaces, biology, and so on.

Hydrophobic Modification of Natural Cellulose Fiber with MMA via Surface-Initiated ARGET ATRP

2011 ◽  
Vol 221 ◽  
pp. 90-94 ◽  
Author(s):  
Gang Li ◽  
Hai Peng Yu ◽  
Yi Xing Liu
Keyword(s):  
Contact Angle ◽  
Reaction Time ◽  
Cotton Fiber ◽  
Fiber Surface ◽  
Cellulose Fiber ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Natural Cellulose ◽  
Arget Atrp ◽  
Contact Angle Analysis

To convert the hydrophilic cotton fiber into hydrophobic, grafting methyl methacrylate (MMA) on cotton fiber surface using ARGET (activators regenerated by electron transfer) ATRP (atom transfer radical polymerization) was studied in this paper. Four parallel experiments with different reaction time (2h/4h/6h/8h) were designed. The modified cotton fibers and the untreated control were examined using FTIR, SEM and contact angle analysis. The results show that as the reaction time prolonged, the peak of carbonyl stretching band of 2-bromoester at 1730cm-1 was stronger and the surface of cotton fiber was rougher, which demonstrates MMA has been grafted on the surface of cotton fiber successively and its amount increases with the reaction time. As the results of contact angle measurement, it shows that the hydrophilicity of cotton fiber can easily be modified by grafting of MMA, but the increasing amount of grafting chain had no obvious effects on further improving its hydrophobicity.

scholarly journals A metallic anti-biofouling surface with a hierarchical topography containing nanostructures on curved micro-riblets

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Taekyung Kim ◽  
Sunmok Kwon ◽  
Jeehyeon Lee ◽  
Joon Sang Lee ◽  
Shinill Kang
Keyword(s):  
Contact Angle ◽  
Hierarchical Structures ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Bacterial Attachment ◽  
Resistance Testing ◽  
Metallic Surface ◽  
Metallic Surfaces ◽  
Hydration Layer ◽  
Surface Finishes

AbstractMetallic surface finishes have been used in the anti-biofouling, but it is very difficult to produce surfaces with hierarchically ordered structures. In the present study, anti-biofouling metallic surfaces with nanostructures superimposed on curved micro-riblets were produced via top-down fabrication. According to the attachment theory, these surfaces feature few attachment points for organisms, the nanostructures prevent the attachment of bacteria and algal zoospores, while the micro-riblets prohibit the settlement of macrofoulers. Anodic oxidation was performed to induce superhydrophilicity. It forms a hydration layer on the surface, which physically blocks foulant adsorption along with the anti-biofouling topography. We characterized the surfaces via scanning electron and atomic force microscopy, contact-angle measurement, and wear-resistance testing. The contact angle of the hierarchical structures was less than 1°. Laboratory settlement assays verified that bacterial attachment was dramatically reduced by the nanostructures and/or the hydration layer, attributable to superhydrophilicity. The micro-riblets prohibited the settlement of macrofoulers. Over 77 days of static immersion in the sea during summer, the metallic surface showed significantly less biofouling compared to a surface painted with an anticorrosive coating.

Improvement of Hydrophilic Properties on Electrospun Polyacrylonitrile Fabrics Surface by Plasma Treatment

2011 ◽  
Vol 213 ◽  
pp. 103-106
Author(s):  
A. Thongphud ◽  
P. Visal-athaphand ◽  
Pitt Supaphol ◽  
Boonchoat Paosawatyanyong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Contact Angle ◽  
Plasma Treatment ◽  
Inductively Couple Plasma ◽  
Chemical Properties ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Measured Contact Angle ◽  
Scanning Electron

Electrospun polyacrylonitrile (PAN) fabrics were prepared by electrospinning with 7%w/v concentration to dissolve in dimethylformamide (DMF) and spinning time 12 h. Radio frequency inductively couple plasma (RF-ICP) at 13.56 MHz were used to improve PAN fabrics surface by O2 gas in plasma treatment that became to hydrophilic properties of PAN fabrics surface. Physical properties were determined by scanning electron microscopy (SEM) and contact angle measurement which found that characterized on PAN fabrics surface after plasma treatment with increased treated time had been damaged on these fabrics surface which measured contact angle measurement with water were range 29.3 to 74.7. Chemical properties were analysed by fourier transform infrared spectroscopy (FTIR) that had been found peak intensities of aliphatic C-H band at 1450 and 2930 cm-1 and peak intensities of cyclic C=O bands at 1732 cm-1 and peak intensities of saturated nitriles at 2243 cm-1 and peak intensities of hydroxyl O-H band at 3600-3650 cm-1.

scholarly journals Superhydrophobic functionalized cellulosic paper by copper hydroxide nanorods for oils purification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  
Keyword(s):  
Contact Angle ◽  
Filter Paper ◽  
Separation Efficiency ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Absorption Capacity ◽  
Morphological Properties ◽  
Copper Hydroxide ◽  
Immersion Method ◽  
Water Contact

AbstractOily water contamination has been sighted as one of the most global environmental pollution. Herein, copper hydroxide nanorods layer was constructed onto cellulosic filter paper surface cured with polydopamine, Ag nanoparticles, and Cu NPs through immersion method. This work has been aimed to produce a superhydrophobic and superoleophilic cellulosic filter paper. The structure, crystalline, and morphological properties of these modified cellulosic filter paper were investigated. Scanning electron microscope images confirmed that the modified surface was rougher compared with the pristine surface. The contact angle measurement confirmed the hydrophobic nature of these modified surfaces with a water contact angle of 169.7°. The absorption capacity was 8.2 g/g for diesel oil and the separation efficiency was higher than 99%. It was noted that the flux in the case of low viscosity solvent as n-hexane was 9663.5 Lm−2 h−1, while for the viscous oil as diesel was 1452.7 Lm−2 h−1.

Preparation and the Blood Compatibility of Titanium Oxide Nanorod Arrays

2011 ◽  
Vol 306-307 ◽  
pp. 25-30 ◽  
Author(s):  
Ping Luo ◽  
Zhan Yun Huang ◽  
Di Hu Chen
Keyword(s):  
Contact Angle ◽  
Surface Morphology ◽  
Titanium Oxide ◽  
Tin Oxide ◽  
Growth Parameters ◽  
Blood Compatibility ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Nanorod Arrays ◽  
Wetting Properties

In this work, titanium oxide nanorod arrays were fabricated by using the hydrothermal method on fluorine-doped tin oxide (FTO) coated glass. The diameter of the nanorods could be controlled from 150 nm to 30 nm by changing the growth parameters. The surface morphology and the structure of the samples were characterized by SEM and XRD. The wetting properties were identified by contact angle measurement. Platelet attachment was investigated to evaluate the blood compatibility of the samples with different nanoscale topographies. Results show that the nanotopographical surfaces perform outstanding blood compatibility, and the adhering platelet decreased with the increasing diameter of the nanorods.

Measurement of wheel-terrain contact angle for WMRs on rough terrain using laser scanning sensor

2017 ◽  
Vol 44 (6) ◽  
pp. 798-807 ◽  
Author(s):  
He Xu ◽  
Yan Xu ◽  
Peiyuan Wang ◽  
Hongpeng Yu ◽  
Ozoemena Anthony Ani ◽  
...  
Keyword(s):  
Contact Angle ◽  
Laser Scanning ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Rough Terrain ◽  
Wheeled Mobile Robots ◽  
Wheel Slip ◽  
Content Type ◽  
Terrain Model ◽  
Measurement Approach

Purpose The purpose of this paper is to explore a novel measurement approach for wheel-terrain contact angle using laser scanning sensors based on near-terrain perception. Laser scanning sensors have rarely been applied to the measurement of wheel-terrain contact angle for wheeled mobile robots (WMRs) in previous studies; however, it is an effective way to measure wheel-terrain contact angle directly with the advantages of simple, fast and high accuracy. Design/methodology/approach First, kinematics model for a WMR moving on rough terrain was developed, taking into consideration wheel slip and wheel-terrain contact angle. Second, the measurement principles of wheel-terrain contact angle using laser scanning sensors was presented, including “rigid wheel - rigid terrain” model and “rigid wheel - deformable terrain” model. Findings In the proposed approach, the measurement of wheel-terrain contact angle using laser scanning sensors was successfully demonstrated. The rationality of the approach was verified by experiments on rigid and sandy terrains with satisfactory results. Originality/value This paper proposes a novel, fast and effective wheel-terrain contact angle measurement approach for WMRs moving on both rigid and deformable terrains, using laser scanning sensors.

Contact angle measurement on rough surfaces

2004 ◽  
Vol 274 (2) ◽  
pp. 637-644 ◽  
Author(s):  
Tammar S. Meiron ◽  
Abraham Marmur ◽  
I.Sam Saguy
Keyword(s):  
Contact Angle ◽  
Rough Surfaces ◽  
Contact Angle Measurement ◽  
Angle Measurement

Curing Time and Water Repellent Properties of Dammar-Titanium Dioxide Thin Film

2015 ◽  
Vol 1112 ◽  
pp. 359-362
Author(s):  
Aisyah Nor Hasnan ◽  
Azizah Hanom Ahmad
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Repellent ◽  
Coating System ◽  
Curing Time ◽  
Coating Surface ◽  
Natural Resin ◽  
Before And After

Dammar plant resin is a local natural resin that can be bled from Dipterocaupacea sp of tree. It can be found abundantly in Malaysia’s tropical forest especially in Sarawak. Dammar and Titanium Dioxide was mixed in a various wt% to produce Dammar-modified Titanium Dioxide coating system. The modified coating systems were then spin-coated onto Aluminium Q-panel as the substrate. Coated Q-panels were left to cure at room temperature. The curing time was evaluated using dust free stage. The addition of Titanium Dioxide into the coating system fastens the curing time taken for the coated Q-panel to be cure. It only took about 11-12 minutes to dry compared to the coating system before the addition of Titanium Dioxide where a quite long duration required, 32 minutes. Contact angle measurement was also carried out in order to determine the wettability of the coating system. The surface coated with dammar-modified titanium dioxide found to be hydrophobic where a quite large contact angle obtained for the sample with 3 wt% of Titanium Dioxide (PDT3). The water droplets actually rest on the coating surface without wetting the surface. Water absorption test was done to strengthen the contact angle results where coated substrate was soaked into distilled water for 24 hours and being weighed before and after soaking. The difference of before and after soaking weigh showed that the coating surface does not absorb that much water where only approximately 0.02% of water being absorbed by the coating system for 3 wt%. It proved that the coating systems applied are hydrophobic.

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