A comparison of contact angle measurement techniques applied to highly porous catalyst supports

2013 ◽  
Vol 233 ◽  
pp. 52-64 ◽  
Author(s):  
Emilia Nowak ◽  
Gary Combes ◽  
E. Hugh Stitt ◽  
Andrzej W. Pacek
Keyword(s):  
Contact Angle ◽  
Measurement Techniques ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Catalyst Supports ◽  
Porous Catalyst ◽  
Highly Porous

Measurement of Wood Wettability by the Wilhelmy Method. Part 1. Contamination of Probe Liquids by Extractives

Holzforschung ◽  
2001 ◽  
Vol 55 (1) ◽  
pp. 21-32 ◽  
Author(s):  
M.E.P. Wålinder ◽  
I. Johansson
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Measurement Techniques ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Liquid Interface ◽  
Wood Extractives ◽  
And Control

Summary This work focuses on the influence of extractives during wetting measurements on wood. Fresh and aged veneers of extracted and non-extracted heart- and sapwood of pine were prepared, and the Wilhelmy method was used to study the wettability of these veneers. In this method, the force acting on the veneers was measured during immersion in and withdrawal from a series of probe liquids. The results suggest that some of the probe liquids become severely contaminated by extractives during the measurements on the non-extracted veneers, and that this strongly affects the wood wetting measurements. The contamination is effectively detected as a distinct decrease in the surface tension of the liquids caused by dissolution or presence of wood extractives at the wood-liquid interface. It is important to note that such contamination may also occur during wetting studies on wood using other contact angle measurement techniques. The most obvious contamination occurred in the case of measurements on non-extracted veneers immersed in water and formamide. Generally, no contamination was detected in the case of measurements on extracted wood veneers. The Wilhelmy method may provide an efficient means for recording and control of any contamination of the probe liquids that may arise during wetting studies on wood.

On the Influence of Relative Humidity on the Contact Angle of a Water Droplet on a Silicon Wafer

2013 ◽  
Author(s):  
J. L. Perez-Diaz ◽  
M. A. Alvarez-Valenzuela ◽  
I. Valiente-Blanco ◽  
S. Jimenez-Lopez ◽  
M. Palacios-Cuesta ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Relative Humidity ◽  
Silicon Wafer ◽  
Water Droplet ◽  
Measurement Techniques ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Wafer Surface ◽  
Free Energy Surface

Contact angle analysis of liquids on surfaces has been extensively used to evaluating solid surface free energy, surface tension, and surface wetting characteristics. Despite the great interest in the contact angle, reported measurements has shown a high variety, which is often related to different contact angle measurement techniques or substrate preparation and oxidation among others. In addition, it is well know, that surface tension and contact angle are modified with temperature. However, no attention has been paid to the influence of the relative humidity (RH) in surface tension or contact angle measurements. In a previous work, we have demonstrated that (for a constant temperature) surface tension on a suspended droplet decreases linearly with RH in the air. In this paper, contact angle of a water droplet on a silicon wafer surface is studied and its relationship with the relative humidity in the air investigated.

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 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.

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