scholarly journals A comparison of contact angle measurement results obtained on bare, treated, and coated alloy samples by both dynamic sessile drop and Wilhelmy method

2014 ◽  
Vol 58 (Supplement) ◽  
pp. 53-59 ◽  
Author(s):  
Loránd Románszki ◽  
Miklós Mohos ◽  
Judit Telegdi ◽  
Zsófia Keresztes ◽  
Lajos Nyikos
Author(s):  
Чуйко М.М. ◽  
Завальський В.

High quality of the soldering process can be achieved with the right choice of the necessary soldering materials. Since wetting determines the further nature of the connection between the solder and the main soldering material, the contact angle  measurement  is the basis for quality control of soldering materials, provided that the basic requirements of the technological process. The determination of the contact angle value is carried out by the indirect method of the sessile drop, by measuring the basic parameters of the drop using infrared transducer. A smaller value of the contact angle corresponds to a better interaction of materials, and hence a better electrical contact


2014 ◽  
Vol 609-610 ◽  
pp. 357-361
Author(s):  
Wei Wei An ◽  
Xiao Li Zhao ◽  
Le Gu ◽  
Run Zhou Su

In this work, carbon films were deposited by magnetron sputtering on silicon substrate. The effect of sputtering time on the surface wettability and mechanical properties of carbon films was investigated. Contact angle measurement was used to analyse surface wettability, and the nanomechanical properties were characterized by nanoindentation. In experiments, the sputtering time was 45 min, 60 min, 75 min and 90 min. The measurement results show that the maximum film hardness was achieved for sputtering time 90 min, with a value of 2.34 GPa. Longer sputtering time resulted in preferable mechanical properties. It was analyzed that the size of the crystal grains on the substrate surface and thickness of the films were increased with the increment of sputtering time. The surface roughness decreased with the increase of sputtering time. Moreover, Youngs modulus increased with sputtering time and the maximum value was 16.94 GPa. The contact angle measurement results show that the prepared films take on the hydrophilicity. The minimum contact angle was achieved for sputtering time 45 min with a value of 54o.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 681 ◽  
Author(s):  
Mateusz Niedźwiedź ◽  
Władysław Skoneczny ◽  
Marek Bara

This article presents the influence of the anodizing parameters and thermo-chemical treatment of Al2O3 coatings made on aluminum alloy EN AW-5251 on the surface free energy. The oxide coating was produced by DC (Direct Current) anodizing in a ternary electrolyte. The thermo-chemical treatment of the oxide coatings was carried out using distilled water, sodium dichromate and sodium sulphate. Micrographs of the surface of the Al2O3 coatings were characterized using a scanning microscope (SEM). The chemical composition of the oxide coatings was identified using EDS (Energy Dispersive X-ray Spectroscopy) microanalysis. Surface free energy (SFE) calculations were performed by the Owens–Wendt method, based on wetting angle measurements made using the sessile drop technique. The highest value of surface free energy for the only anodized coatings was 46.57 mJ/m2, and the lowest was 37.66 mJ/m2. The contact angle measurement with glycerine was 98.06° ± 2.62°, suggesting a hydrophobic surface. The thermo-chemical treatment of the oxide coatings for most samples contributed to a significant increase in SFE, while reducing the contact angle with water. The highest value of surface free energy for the coatings after thermo-chemical treatment was 77.94 mJ/m2, while the lowest was 34.98 mJ/m2. Taking into account the contact angle measurement with glycerine, it was possible to obtain hydrophobic layers with the highest angle of 109.82° ± 4.79° for the sample after thermal treatment in sodium sulphate.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  

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.


2011 ◽  
Vol 306-307 ◽  
pp. 25-30 ◽  
Author(s):  
Ping Luo ◽  
Zhan Yun Huang ◽  
Di Hu Chen

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.


Author(s):  
He Xu ◽  
Yan Xu ◽  
Peiyuan Wang ◽  
Hongpeng Yu ◽  
Ozoemena Anthony Ani ◽  
...  

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.


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