scholarly journals Detailed Characterization of the Effect of Application of Commercially Available Surface Treatment Agents on Textile Wetting Behavior

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 219 ◽  
Author(s):  
Johannes Staudt ◽  
Stephan Leyer ◽  
John Duchowski

The change in the wetting behavior of a standard commercially available textile material in response to surface treatment has been thoroughly characterized with conventional laboratory measurement techniques. The characterization was carried out by taking a series of contact angle measurements that allowed for the determination of the corresponding shift in substrate surface energy as a result of the applied treatment. The collected surface energy values were expressed in terms of the spreading parameter S, which was used to describe phase behavior at the substrate/droplet interface. However, these results showed that the use of a coarse parameter S, or even the work of adhesion ( W a ) and the work of cohesion ( W c ) parameters alone did not adequately account for the observed wetting behavior. A proper description of droplet formation on substrate surface was provided only when the interfacial interaction was examined at a more detailed level by involving the individual dispersive ( σ l d , σ s d ) and polar ( σ l p , σ s p ) surface energy components of both the solid and the wetting liquid. The methodology for characterization of interactions between a textile substrate coated with various surface active agents and several functional fluids have been developed. Several practical examples of how this methodology can be applied to describe the substrate surface treatment and the resulting wetting behavior are described herein.

Author(s):  
C. Mathew Mate ◽  
Robert W. Carpick

The energies associated with surfaces—surface energy, interfacial energy, surface tension, and work of adhesion—drive many surface and interfacial phenomena including tribological ones such as adhesion and friction. This chapter discusses the physical origins of surface energies for liquids and solids, and how the concepts of capillary pressure, capillary condensation, wetting, and work of adhesion are derived from surface energy. Further, this chapter covers the different methods for measuring surface energies, including the most common method for solid surfaces: contact angle measurements of liquid droplets on surfaces. This chapter also introduces how surface energies and surface tensions lead to adhesion and adhesion hysteresis between contacting surfaces, which is followed up in the subsequent chapters on surface forces.


2021 ◽  
Vol 6 ◽  
Author(s):  
A. Tiwari ◽  
T. Tolpekina ◽  
Hans van Benthem ◽  
M. K. Gunnewiek ◽  
B. N. J. Persson

We study the influence of the surface energy and contamination films on rubber adhesion and sliding friction. We find that there is a transfer of molecules from the rubber to the substrate which reduces the work of adhesion and makes the rubber friction insensitive to the substrate surface energy. We show that there is no simple relation between adhesion and friction: adhesion is due to (vertical) detachment processes at the edge of the contact regions (opening crack propagation), while friction in many cases is determined mainly by (tangential) stick-slip instabilities of nanosized regions, within the whole sliding contact. Thus while the pull-off force in fluids may be strongly reduced (due to a reduction of the work of adhesion), the sliding friction may be only slightly affected as the area of real contact may be dry, and the frictional shear stress in the contact area nearly unaffected by the fluid.


2004 ◽  
Vol 25 (23) ◽  
pp. 1958-1962 ◽  
Author(s):  
Sanne Wijnans ◽  
Berend-Jan de Gans ◽  
Frank Wiesbrock ◽  
Richard Hoogenboom ◽  
Ulrich S. Schubert

Author(s):  
C.M. Sung ◽  
M. Levinson ◽  
M. Tabasky ◽  
K. Ostreicher ◽  
B.M. Ditchek

Directionally solidified Si/TaSi2 eutectic composites for the development of electronic devices (e.g. photodiodes and field-emission cathodes) were made using a Czochralski growth technique. High quality epitaxial growth of silicon on the eutectic composite substrates requires a clean silicon substrate surface prior to the growth process. Hence a preepitaxial surface cleaning step is highly desirable. The purpose of this paper is to investigate the effect of surface cleaning methods on the epilayer/substrate interface and the characterization of silicon epilayers grown on Si/TaSi2 substrates by TEM.Wafers were cut normal to the <111> growth axis of the silicon matrix from an approximately 1 cm diameter Si/TaSi2 composite boule. Four pre-treatments were employed to remove native oxide and other contaminants: 1) No treatment, 2) HF only; 3) HC1 only; and 4) both HF and HCl. The cross-sectional specimens for TEM study were prepared by cutting the bulk sample into sheets perpendicular to the TaSi2 fiber axes. The material was then prepared in the usual manner to produce samples having a thickness of 10μm. The final step was ion milling in Ar+ until breakthrough occurred. The TEM samples were then analyzed at 120 keV using the Philips EM400T.


2013 ◽  
Vol 51 (10) ◽  
pp. 735-741
Author(s):  
Dong-Yong Kim ◽  
Eun-Wook Jeong ◽  
Kwun Nam Hui ◽  
Youngson Choe ◽  
Jung-Ho Han ◽  
...  

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.


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