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.

scholarly journals Simple method of fabrication of hydrophobic coatings for polyurethanes

2011 ◽  
Vol 9 (6) ◽  
pp. 1039-1045 ◽  
Author(s):  
Beata Butruk ◽  
Paulina Ziętek ◽  
Tomasz Ciach
Keyword(s):  
Contact Angle ◽  
High Efficiency ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Acoustic Microscopy ◽  
Water Contact ◽  
Simple Method ◽  
Hydrophobic Coatings ◽  
Grafting Reaction

AbstractThe aim of this study was to develop a method of manufacturing versatile hydrophobic coatings for polymers. Authors present a simple technique of polyurethane (PU) surface modification with covalently attached silicones (PDMS) or fluorocarbons (PFC). Diisocyanates were applied as linker molecules. The obtained coatings were characterized using spectroscopic analysis (FTIR), scanning acoustic microscopy (SAM) and water contact angle measurements. FTIR analysis revealed high efficiency of grafting reaction. The results of contact angle measurement indicated significant increase of hydrophobicity — from 66° (unmodified PU) to 113° (PU grafted with PDMS) and 118° (PU grafted with PFC). Acoustic microscopy analysis confirmed satisfactory homogeneity and smoothness of the fabricated layers. In vitro cell tests revealed non-adherent properties of the surfaces. Both, MTT assay and fluorescence staining confirmed non-cytotoxicity of the coatings, which makes them potential candidates for use in biomedical applications.

Preparation of Flower-Like ZnO Micro-Sphere Powders and their Surface Wettability Modification

2011 ◽  
Vol 412 ◽  
pp. 17-20 ◽  
Author(s):  
Bing Li ◽  
Chang Song Liu ◽  
Yu Bin Qi ◽  
Da Chun Cao ◽  
Yong Wan
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Surface Wettability ◽  
Water Contact ◽  
Simple Method ◽  
High Adhesion ◽  
Zno Powders ◽  
Micro Sphere

Three-dimensitional flower-like ZnO powders were prepared by using a simple aqueous solution method. Their surface wettability was modified via some long chain alkylsilanes with low surface energy. The microstructures and the wettability properties were studied by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and contact angle measurement (CAM). The ZnO powders are spheric and are about 5 micrometers in diameter. The boundary of the microspheres are not smooth, but petaliform in nanoscale, which demonstrate a hierarchical microstructure. The as-synthesized powders have a superhydrophobicity with water contact angle of more than 150°, and have a high adhesion to water. After modified by alkylsilanes, however, the ZnO powders demonstrate a strong anti-adhesion to water. When modified by fluorinated alkylsilanes, the surface of ZnO microspheres had a water contact angle up to 170°. Also, the water droplet could bounce against the surface just like a spring ball, and there are not any water traces left when the water droplets contact the surfaces of ZnO powders. The results provide a simple method to repel the water wetting and will be helpful to disperse the powders especially in a humid environment.

Fabrication of Transparent Hydrophilic Nanosized TiO2 Films via Layer-by-Layer Self-Assembly

2016 ◽  
Vol 852 ◽  
pp. 1075-1079
Author(s):  
Zhi Yong Zeng ◽  
Ying Shi ◽  
Su Jun Yuan ◽  
Jian Jun Xie
Keyword(s):  
Contact Angle ◽  
Self Assembly ◽  
Hydrothermal Process ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Layer By Layer ◽  
Water Contact ◽  
Assembly Method ◽  
Oppositely Charged ◽  
Positively Charged

The transparent nanosized TiO2 film was fabricated by a layer-by-layer assembly method starting from the highly dispersed anatase oppositely charged TiO2 nanoparticles without using anypoly electrolytes. The positively charged TiO2 nanoparticles (ca.7 nm) and negatively charged TiO2 nanoparticles (ca.7 nm) were synthesized by a subsequently hydrothermal process. Field-emission scanning electron microscopy, UV-vis transmittance spectra and Contact angle measurement were employed to characterize TiO2films.By the treatment of 500°C for 2hrs, the nanostructured TiO2 film showed a water contact angle of below 10°andthe relative transmittance to quartz glass of over 90%.

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.

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.

Preparation of TiO2–SiO2 Hybrid Nanosols Coated Flame-Retardant Polyester Fabric Possessing Dual Contradictory Characteristics of Superhydrophobicity and Self Cleaning Ability

2020 ◽  
Vol 20 (3) ◽  
pp. 1780-1789 ◽  
Author(s):  
Priyanka Katiyar ◽  
Shraddha Mishra ◽  
Anurag Srivastava ◽  
N. Eswara Prasad
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Flame Retardant ◽  
Protective Clothing ◽  
Sol Gel ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Vis Spectroscopy ◽  
Self Cleaning

TiO2, SiO2 and their hybrid nanocoatings are prepared on inherent flame retardant textile substrates from titanium(IV)iso-proproxide (TTIP) and tetraethoxysilane (TEOS) precursors using a sol–gel process followed by hydrothermal treatment. The coated samples are further functionalized by hexadecyltrimethoxysilane (HDTMS) to impart superhydrophobicity. Sample characterization of the nanosols, nanoparticles and coated samples are investigated using, X-ray diffractometer, transmission electron microscopy, scanning electron microscopy, UV-Vis spectroscopy, contact angle measurement. Stain degradation test under mild UV irradiation shows almost 54% degradation of coffee stain within 4 hours measured by Spectrophotometer. UV-Vis Absorption Spectroscopy demonstrates complete degradation of methyl orange colorant within 3 hours. Hybrid nanosol coated and HDTMS modified inherent flame retardant polyester surfaces show apparent water contact angle as ~145°, which is much closer to proximity of superhydrophobic surfaces. Thus, the novelty of present work is, by using sol–gel technique, a bi-functional textile surface has been developed which qualifies the very specific requirements of protective clothing like self-cleaning property (imparted by TiO2 nanoparticles) and superhydrophobicity (imparted by SiO2 nanoparticles and further surface modification by HDTMS), which are entirely contradictory in nature, in a single fabric itself. Thus developed textile surfaces also possess the other attributes of protective clothing like flame retardancy and air permeability.

Effect of Plasma-Induced Polymerization on Contact Angle of Paper

2011 ◽  
Vol 396-398 ◽  
pp. 1619-1623
Author(s):  
Zhao Ping Song ◽  
Jun Rong Li ◽  
Hui Ning Xiao
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Polymer Grafting ◽  
Hydrophobic Property ◽  
Cellulose Fibres ◽  
Water Contact ◽  
X Ray ◽  
Factors Associated

Hydrophobic modification of cellulose fibres was conducted by plasma-induced polymer grafting in an attempt to increase the hydrophobicity of paper. Two hydrophobic monomers, i.e., butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA) were grafted on cellulose fibres, induced by atmospheric cold plasma. Various influencing factors associated with the plasma-induced grafting were investigated, including the contact time and reaction temperature with monomers, and the dosage of monomers. Contact-angle measurement, infrared spectrum (IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used to ascertain the occurrence of the grafting. The results showed that the hydrophobic property of the modified paper sheet was improved significantly after the plasma-induced grafting. The water contact angle on the surface of the paper reached up to higher than125°.

Picoliter Water Contact Angle Measurement on Polymers

Langmuir ◽  
2007 ◽  
Vol 23 (13) ◽  
pp. 6875-6878 ◽  
Author(s):  
Michael Taylor ◽  
Andrew J. Urquhart ◽  
Mischa Zelzer ◽  
Martyn C. Davies ◽  
Morgan R. Alexander
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Water Contact Angle Measurement

Physicochemical characterization of actinomycetes isolated from decayed cedar wood: contact angle measurement

2014 ◽  
Vol 28 (20) ◽  
pp. 2046-2053 ◽  
Author(s):  
Hajar Maataoui ◽  
Hassan Barkai ◽  
Moulay Sadiki ◽  
Abdellatif Haggoud ◽  
Saad Ibnsouda Koraichi ◽  
...  
Keyword(s):  
Contact Angle ◽  
Physicochemical Characterization ◽  
Contact Angle Measurement ◽  
Angle Measurement
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