We study the adhesion, friction and leak rate of seals for four different elastomers: Acrylonitrile Butadiene Rubber (NBR), Ethylene Propylene Diene (EPDM), Polyepichlorohydrin (GECO) and Polydimethylsiloxane (PDMS). Adhesion between smooth clean glass balls and all the elastomers is studied both in the dry state and in water. In water, adhesion is observed for the NBR and PDMS elastomers, but not for the EPDM and GECO elastomers, which we attribute to the differences in surface energy and dewetting. The leakage of water is studied with rubber square-ring seals squeezed against sandblasted glass surfaces. Here we observe a strongly non-linear dependence of the leak rate on the water pressure ΔP for the elastomers exhibiting adhesion in water, while the leak rate depends nearly linearly on ΔP for the other elastomers. We attribute the non-linearity to some adhesion-related phenomena, such as dewetting or the (time-dependent) formation of gas bubbles, which blocks fluid flow channels. Finally, rubber friction is studied at low sliding speeds using smooth glass and sandblasted glass as substrates, both in the dry state and in water. The measured friction coefficients are compared to theory, and the origin of the frictional shear stress acting in the area of real contact is discussed. The NBR rubber, which exhibits the strongest adhesion both in the dry state and in water, also shows the highest friction both in the dry state and in water.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c7sm02038d | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Relationship between the density of in soil at harvest evaluated using real-time PCR and sweetpotato disease incidence.
Plant Dis
January 2025
Henan University of Science and Technology, agricultural college, Luoyang, [Select a State/Province], China;
Sweetpotato Stem Rot Nematode () causes the most devastating disease affecting sweetpotato production in China. The objectives of this study were: i) establish a quantification method using real-time PCR for of sweetpotato; ii) analyze the effect of density at harvest on the percentage of disease incidence in sweetpotatoes; and iii) evaluate the effect of soil physical properties on disease incidence. Populations of isolated from 28 different production areas in Henan Province exhibited identical sequences, and then real-time PCR specific primers (PRNf and PRNr) were designed.
View Article and Find Full Text PDFTherapeutic benefits of glycerol in dry eye disease.
Front Med (Lausanne)
January 2025
Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States.
Dry eye disease (DED) is one of the most commonly diagnosed eye disorders, with a prevalence ranging from 5 to 50%, depending on the geographic location. DED is a multifactorial disorder of the tears and ocular surface, which results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. It is also accompanied by increased osmolarity of the tear film and inflammation of the surface of the eye.
View Article and Find Full Text PDFA portable EEG signal acquisition system and a limited-electrode channel classification network for SSVEP.
Front Neurorobot
January 2025
College of Engineering, Qufu Normal University, Rizhao, China.
Brain-computer interfaces (BCIs) have garnered significant research attention, yet their complexity has hindered widespread adoption in daily life. Most current electroencephalography (EEG) systems rely on wet electrodes and numerous electrodes to enhance signal quality, making them impractical for everyday use. Portable and wearable devices offer a promising solution, but the limited number of electrodes in specific regions can lead to missing channels and reduced BCI performance.
View Article and Find Full Text PDFActivation and Catalysis of Methane over Metal-Organic Framework Materials.
Acc Mater Res
January 2025
Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K.
Methane (CH), which is the main component of natural gas, is an abundant and widely available carbon resource. However, CH has a low energy density of only 36 kJ L under ambient conditions, which is significantly lower than that of gasoline (. 34 MJ L).
View Article and Find Full Text PDFFiber Sorbents - A Versatile Platform for Sorption-Based Gas Separations.
Acc Mater Res
January 2025
School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30322, United States.
Increasing demand for high-purity fine chemicals and a drive for process intensification of large-scale separations have driven significant work on the development of highly engineered porous materials with promise for sorption-based separations. While sorptive separations in porous materials offer energy-efficient alternatives to longstanding thermal-based methods, the particulate nature of many of these sorbents has sometimes limited their large-scale deployment in high-throughput applications such as gas separations, for which the necessary high feed flow rates and gas velocities accrue prohibitive operational costs. These processability limitations have been historically addressed through powder shaping methods aimed at the fabrication of structured sorbent contactors based on pellets, beads or monoliths, commonly obtained as extrudates.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!