Surface energy of preservative-treated southern yellow pine (Pinus spp.) by contact angle measurement

2007 ◽  
Vol 2 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Jinzhen Cao ◽  
Pascal D. Kamdem
2009 ◽  
Vol 16 (06) ◽  
pp. 801-806 ◽  
Author(s):  
Y. C. GUAN ◽  
W. ZHOU ◽  
H. Y. ZHENG

Laser surface melting is known to alter surface energy and wettability of a few engineering materials, but its effect on magnesium alloys has never been reported. Effort was made to study how Nd : YAG laser irradiation influenced surface energy of an AZ91D magnesium alloy. Contact angle measurement was carried out using three types of liquids to make it possible to calculate the surface energy quantitatively based upon the acid–base theory. The laser irradiation was found to enhance surface wettability significantly and lead to a drastic increase in surface energy from 25.82 to 40.78 mJ/m2. The change in surface property was attributed to the laser-induced refinement of α- Mg and β- Mg 17 Al 12 phases and enrichment of Al in the microstructure.


2002 ◽  
Vol 16 (06n07) ◽  
pp. 1031-1037 ◽  
Author(s):  
J. S. CHEN ◽  
S. P. LAU ◽  
Z. SUN ◽  
G. Y. CHEN ◽  
Y. J. LI ◽  
...  

Ta-C and iron containing amorphous carbon (a-C:Fe) films were deposited by filtered cathodic vacuum arc technique. The influences of Fe contents on the wettability of the films were investigated in terms of surface energy. The surface energy of a-C:Fe films was determined by the contact angle measurement. Atomic force microscopy (AFM), Raman spectroscopy and X-ray induced photoelectron spectroscopy (XPS) were employed to analyze the origin of the variation of surface energy with various Fe content. It is found that the contact angle for water increases significantly after incorporating Fe into the films and the films become hydrophobic. The roughness of these films has a little effect on the contact angle. The surface energy is reduced after incorporating Fe into the a-C film which is due to the reduction of both dispersive and polar component. The reduction in dispersive component is ascribed to the decrease of atomic density of the a-C:Fe films due to the increase in sp2 bonded carbon. The absorption of oxygen on the surface play an important role in the reduction of polar component for the a-C:Fe films. It is proposed that such network as (Ca-O-Fe)-O-(Fe-O-Ca) may be formed and responsible for the reduction of polar component.


2010 ◽  
Vol 297-301 ◽  
pp. 656-663
Author(s):  
Y.L. Hsu ◽  
C.H. Lee ◽  
S.M. Chiu ◽  
Y.C. Sung ◽  
K.Y. Yang ◽  
...  

The side effect of electrosurgery includes tissue charring, smoke generation and the adhesion of tissue to electrodes. These effects prolong surgery and interfere with effective coagulation. In this paper, CrWNx, CrOx and ZrOx coating were prepared by an unbalanced magnetron sputtering. The microstructure of films was characterized using XRD, XPS, TEM and AFM. The hydrophobicity and surface energy of coatings were calculated by contact angle measurement and Wu harmonic mean approach. Anti-sticking in vitro test was performed by monopolar electrosurgery using pork liver tissue. The hardness of CrWNx , ZrOx and CrOx coatings were 44 GPa, 26.3 GPa and 20.7 GPa, respectively. The CrOx coating had the lowest surface energy 33.5 mN/m and the highest contact angle of water as high as 103°. The high surface O-H bonds density of CrOx coating and N-H bonds density of CrWNx coating could explain about their lower polar component of surface energy. All the three PVD coatings remarkably reduced the quantity of tissue adhesion on the electrode from about 2 times (ZrOx and CrWNx coatings) to 4.88 times (CrOx coating) than uncoated SUS304 electrode.


2011 ◽  
Vol 687 ◽  
pp. 557-561
Author(s):  
Wu Gao Qiu ◽  
Zhan Ping Zhang ◽  
Yu Hong Qi ◽  
Peng Chao Zhang

Silicones coatings were widely used owing to their excellent low surface energy and good flexibility. The structure of the modified multiple wall nanotubes (MWNTs) was tested by IR. Influence of content and sort of MWNTs on microstructures, hydrophobicity of coatings and EIS was investigated using SEM, contact angle measurement (CAM) and electrochemical workstation. The results show that various groups had embedded carbon nanotubes, the coating modified by MWNTs has much lower surface energy than that of the coating wothout modification, the coating modified by different MWNTs have diverse surface energy, and the low-frequency impedance of the coatings was not decreased as the weight of MWNTs increased.


2011 ◽  
Vol 2 ◽  
pp. 1-4 ◽  
Author(s):  
D. P. Subedi

This paper reports a description of the theory of contact angle measurement and its use for the determination of surface energy of solids. The main objective of the work is to present a convenient approach to explain wetting phenomenon using contact angle theory. A brief review of Young’s equation and Young- Dupre equation is also presented followed by an extended Fowke’s equation widely used for the calculation of surface energy of solids. The two liquid model has been applied to determine the surface energy of polycarbonate and low density polyethylene.Key words: Contact angle; Surface energy; Surface characterization; Wettability; Young’s equation; Fowke’s modelThe Himalayan Physics Vol.2, No.2, May, 2011Page:1-4Uploaded Date: 31 July, 2011


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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