Contact Angle of Ethanol and n-Propanol Aqueous Solutions on Metal Surfaces

2011 ◽  
Vol 34 (9) ◽  
pp. 1535-1542 ◽  
Author(s):  
L.-T. Fan ◽  
X.-G. Yuan ◽  
C.-x. Zhou ◽  
A.-W. Zeng ◽  
K.-T. Yu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Aqueous Solutions ◽  
Metal Surfaces

Penetration Dynamics of Solid Particles into Liquids High-Speed Experimental Results and Modelling

2005 ◽  
Vol 473-474 ◽  
pp. 429-434 ◽  
Author(s):  
Olga Verezub ◽  
György Kaptay ◽  
Tomiharu Matsushita ◽  
Kusuhiro Mukai
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Aqueous Solutions ◽  
Particle Velocity ◽  
Weber Number ◽  
High Speed ◽  
Solid Particles ◽  
Bulk Liquid ◽  
Distilled Water ◽  
Critical Weber Number

Penetration of model solid particles (polymer, teflon, nylon, alumina) into transparent model liquids (distilled water and aqueous solutions of KI) were recorded by a high speed (500 frames per second) camera, while the particles were dropped from different heights vertically on the still surface of the liquids. In all cases a cavity has been found to form behind the solid particle, penetrating into the liquid. For each particle/liquid combination the critical dropping height has been measured, above which the particle was able to penetrate into the bulk liquid. Based on this, the critical impact particle velocity, and also the critical Weber number of penetration have been established. The critical Weber number of penetration was modelled as a function of the contact angle, particle size and the ratio of the density of solid particles to the density of the liquid.

Nature of fresh metal surfaces in aqueous solutions

1969 ◽  
Vol 73 (11) ◽  
pp. 3562-3570 ◽  
Author(s):  
Terrell Neils Anderson ◽  
Jeffrey L. Anderson ◽  
Henry Eyring
Keyword(s):  
Aqueous Solutions ◽  
Metal Surfaces

Investigation of Surface Modifications of Metals with Low-Pressure Plasma System

2015 ◽  
Vol 239 ◽  
pp. 161-179
Author(s):  
B.A. Soliman ◽  
M.M. Abdelrahman ◽  
F.W. Abdelsalam
Keyword(s):  
Contact Angle ◽  
Metal Surfaces ◽  
Surface Engineering ◽  
Film Growth ◽  
Low Pressure ◽  
Green Technology ◽  
Plasma System ◽  
Argon Gas ◽  
Pressure Plasma ◽  
Low Pressure Plasma

The effects of plasma exposure and impingement of energetic particles are now widely used for substrate cleaning as well as to assist and control thin film growth and various applications. Plasma technology is a versatile green technology used for surface engineering technology. Plasma sources have become a very useful tool for surface modification and deposition of various materials. In this work, typical treatments of the surfaces of Mn, Fe, W and Cu metals were carried out using a low-pressure plasma system with argon gas and operating with an aluminum cathode. The plasma ignition was produced by flowing argon gas between two metal electrodes, and the maximum discharge voltage was 3 kV. All the treated metal samples were exposed to the plasma for a constant time of 2 hours. The modified metal surfaces were characterized by in situ X-ray florescence spectroscopy (XRF), contact angle measurements and scanning electron microscopy (SEM). The wetting behavior of the treated metal surfaces was studied by employing the contact angle method. The contact angle is found to be dependable on the surface layer properties of the metals which in turn is affected by the dose time.

Preparation and Characterization of Heparin-Immobilized Poly(Ether Urethanes)

2011 ◽  
Vol 393-395 ◽  
pp. 236-239
Author(s):  
Li Ming Lian ◽  
Bing Leng ◽  
Xiao Hua Ma
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Aqueous Solutions ◽  
Fourier Transform Infrared Spectroscopy ◽  
Toluidine Blue ◽  
Water Contact ◽  
The Fourier Transform ◽  
Hydrolysis Of

Heparin (Hep)-immobilized poly(ether urethanes) (PU) was prepared by a unique preparation procedure. Firstly, the poly(ether urethanes)(PU) containing diester groups in the side chains were synthesized. Then, PU was dispersed in aqueous solutions and immobilized with heparin after the hydrolysis of diester groups and carboxylation. The Fourier transform infrared spectroscopy (FTIR) and water contact angle (WCA) were used to characterize the heparin-bonded PU. The amount of heparin grafted on the PU was determined to be 0.57wt.% by the toluidine blue method. The heparin-immobilized PU could release just 12% of the immobilized heparin in the early 10 hours of the 70 hours immobilized heparin stability test.

Preparation features of metal surfaces of machine parts before gluing

2021 ◽  
Vol 0 (12) ◽  
pp. 13-16
Author(s):  
E. A. Kosenko ◽  
◽  
D. K. Zakorsky ◽  
A. Du ◽  
N.K. Podchuvalova ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Metal Surfaces ◽  
Chemical Method ◽  
Copper Slag ◽  
Strength Test ◽  
Test Results ◽  
Shot Blasting ◽  
Adhesive Bonds ◽  
Mechanical Methods ◽  
Machine Parts

The chemical and mechanical methods of preparing metal surfaces before gluing have been examined. The strength test results for shear of adhesive bonds of aluminum and steel samples, the surfaces of which were prepared by grinding, shot-blasting with copper slag and chemical treatment in aqueous solutions of acids before gluing. The best results for shear strength of adhesive bonds are observed for samples whose surfaces were subjected to shot blasting with a copper slag, the worst ones are after chemical method of preparing in aqueous solutions of acids.

The Wetting of Insect Cuticle

1950 ◽  
Vol 41 (1) ◽  
pp. 121-139 ◽  
Author(s):  
Rajindar Pal
Keyword(s):  
Contact Angle ◽  
Aqueous Solutions ◽  
Contact Angles ◽  
The Body ◽  
Insect Cuticle ◽  
Cuticular Waxes ◽  
Mineral Oils ◽  
Spray Droplets ◽  
Biological Tests ◽  
Wetting Agents

The best method of assessing the wetting powers of liquids is to measure the contact angle formed with a particular solid surface. In order to study the wetting of insects by spray liquids, it was necessary to measure, as rapidly as possible, the contact angles of very small droplets on restricted surfaces (such as portions of the insects). The apparatus used projected a greatly enlarged image of the drop, the outline of which could be traced very quickly and used for subsequent calculations.Under practical conditions, spray droplets impact on insects with some relative velocity either due to drift of the spray particles or to flight movements of the insect.Measurements were therefore made of the contact angles formed by droplets of water of known size falling on to insects (or to a beeswax surface) at a known speed. It was found that with rather large drops (5 mm. diameter) the contact angles formed were somewhat lower than the normal advancing contact angle. With small droplets (0·1-0·5 mm. diameter) there was no difference. Biological tests were made with 30 species of insects, differing widely in the nature of their integument and habitat. The resistance to wetting was found to vary greatly, not only from species to species but also on different parts of the body of a single insect. In general, most of the insects were readily wetted by oils and unwetted by water. Insects withhard cuticular lipoids, such as Tenebrio, were more hydrophobic than the Blattidswith greasy cuticular waxes. A few species were both lipophilic and hydrophilic (larvae of Mamestra, Polia, Musca). Apart from the chemical nature of the cuticle, irregularities and the presence or absence of hairs were important. Increased roughnesslowers the contact angles of liquids with good wetting powers, but has the opposite effect with liquids with poor wetting powers. Measurements were made of thecontact angles formed on individual hairs of Arctia caja larvae by spray droplets. The contact angles formed on these hairs by plain liquids were strongly correlated with the angles formed on smooth Tenebrio cuticle or on an artificial beeswax surface; but there was only very rough correlation between the three sets of data when aqueous solutions of wetting agents were tested.The test liquids included saturated and unsaturated hydrocarbons, mineral oils with varying aromatic contents, organic esters, alcohols and aqueous solutions. Among the hydrocarbons, members of the aliphatic series wet insect cuticle more readily than the aromatic group. The aromatic contents of the oils did not, however, affect their very high wetting powers.The effects of adding surface active agents to aqueous sprays were investigated. Of the samples tested, the most effective wetting agents were those with neutral un-ionised molecules.

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