Surface Chemistry on Colloidal Metals. Reversible Adsorbate-Induced Surface Composition Changes in Colloidal Palladium-Copper Alloys

Langmuir ◽  
1995 ◽  
Vol 11 (3) ◽  
pp. 693-695 ◽  
Author(s):  
John S. Bradley ◽  
Ernestine W. Hill ◽  
Bruno Chaudret ◽  
Anne Duteil
Keyword(s):  
Surface Chemistry ◽  
Surface Composition ◽  
Copper Alloys ◽  
Palladium Copper Alloys ◽  
Composition Changes

scholarly journals Strength, Hardness, and Ductility Evidence of Solid Solution Strengthening and Limited Hydrogen Embrittlement in the Alloy System Palladium-Copper (Cu wt. % 5–25)

Hydrogen ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 262-272
Author(s):  
Sebastian DiMauro ◽  
Gabrielle Legall ◽  
Coleman Lubinsky ◽  
Monica Nadeau ◽  
Renee Tait ◽  
...  
Keyword(s):  
Solid Solution ◽  
Hydrogen Embrittlement ◽  
Copper Content ◽  
Vickers Microhardness ◽  
Copper Alloys ◽  
Alloy System ◽  
Weight Percent ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Palladium Copper Alloys

Strength, hardness, and ductility characteristics were determined for a series of palladium-copper alloys that compositionally vary from 5 to 25 weight percent copper. Alloy specimens subjected to vacuum annealing showed clear evidence of solid solution strengthening. These specimens showed, as a function of increasing copper content, increased yield strength, ultimate strength, and Vickers microhardness, while their ductility was little affected by compositional differences. Annealed alloy specimens subsequently subjected to exposure to hydrogen at 323 K and PH2 = 1 atm showed evidence of hydrogen embrittlement up to a composition of ~15 wt. % Cu. The magnitude of the hydrogen embrittlement decreased with increasing copper content in the alloy.

Surface Composition Changes and Ablation Dynamics in Excimer Laser Irradiated CdTe

1990 ◽  
Vol 191 ◽  
Author(s):  
P. D. Brewer ◽  
J. J. Zinck ◽  
G. L. Olson
Keyword(s):  
Laser Ablation ◽  
Excimer Laser ◽  
Surface Composition ◽  
Laser Ablation Process ◽  
Flight Mass Spectrometry ◽  
Rich Condition ◽  
Thermal Mechanism ◽  
Krf Excimer Laser ◽  
Composition Changes ◽  
Cdte Surface

ABSTRACTWe have investigated the dynamics of KrF excimer laser ablation of CdTe and the fluence dependent changes in surface stoichiometry that accompany the laser ablation process. The composition of the CdTe surface was reversibly controlled between stoichiometric and a Te-rich condition by varying the laser fluence over the range from 15–65 mJ/cm2. The primary species ejected from the irradiated surface were Cd atoms and Te2 molecules. Their velocity distributions as measured by time-of-flight mass spectrometry were found to be Maxwellian. From the analysis of the velocity distributions, the preferential desorption of surface atoms, and the reversible nature of the process, we conclude that the desorption is due to a photo-thermal mechanism which mediates the competition between Te2 formation and desorption and the desorption of Cd atoms.

scholarly journals Surface composition changes of samples during ECR discharge cleaning of JIPP T-IIU and RFC-XX-M.

1986 ◽  
Vol 55 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Yoichiro Hori ◽  
Zensaburo Kabeya ◽  
Nobuaki Noda ◽  
Takayuki Aoki ◽  
Kenya Akaishi ◽  
...  
Keyword(s):  
Surface Composition ◽  
Composition Changes

scholarly journals Identification of Toxicity Parameters Associated with Combustion Produced Soot Surface Chemistry and Particle Structure by in Vitro Assays

Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 345
Author(s):  
Heba Al Housseiny ◽  
Madhu Singh ◽  
Shaneeka Emile ◽  
Marvin Nicoleau ◽  
Randy L. Vander Wal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Surface Chemistry ◽  
Cell Viability ◽  
Health Effects ◽  
Stress Responses ◽  
Surface Composition ◽  
Particle Surface ◽  
In Vitro Assays ◽  
Epithelial Cell Line ◽  
And Oxidative Stress

Air pollution has become the world’s single biggest environmental health risk of the past decade, causing millions of yearly deaths worldwide. One of the dominant air pollutants is fine particulate matter (PM2.5), which is a product of combustion. Exposure to PM2.5 has been associated with decreased lung function, impaired immunity, and exacerbations of lung disease. Accumulating evidence suggests that many of the adverse health effects of PM2.5 exposure are associated with lung inflammation and oxidative stress. While the physical structure and surface chemistry of PM2.5 are surrogate measures of particle oxidative potential, little is known about their contributions to negative health effects. In this study, we used functionalized carbon black particles as surrogates for atmospherically aged combustion-formed soot to assess the effects of PM2.5 surface chemistry in lung cells. We exposed the BEAS-2B lung epithelial cell line to different soot at a range of concentrations and assessed cell viability, inflammation, and oxidative stress. Our results indicate that exposure to soot with varying particle surface composition results in differential cell viability rates, the expression of pro-inflammatory and oxidative stress genes, and protein carbonylation. We conclude that particle surface chemistry, specifically oxygen content, in soot modulates lung cell inflammatory and oxidative stress responses.

Effect of Addition of Hydrogen to the Argon Sheath of a Unidirectional, High-Voltage Spark

1993 ◽  
Vol 47 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Jennifer B. Cappel ◽  
Alexander Scheeline ◽  
Joel M. Goldberg
Keyword(s):  
Surface Chemistry ◽  
High Voltage ◽  
Electrode Surface ◽  
Copper Alloys ◽  
Plasma Chemistry ◽  
Spark Discharge ◽  
Hydrogen Addition ◽  
Ionization Limit

Changes in the spectrum of copper alloys excited with a unidirectional spark discharge in argon are noted when hydrogen is added to the system. Systematic enhancement in erosion of copper, but not of copper in brass or in Muntz metal, is observed. Argon spectra are also perturbed, with some cascades originating near the Ar I ionization limit enhanced while other, nearly isoenergetic, cascades terminating in the Ar I metastable levels are suppressed. Ar II emission is also enhanced in the presence of H2. Both electrode surface chemistry and plasma chemistry are affected by the hydrogen addition.

Tailored Polymer Surfaces

MRS Bulletin ◽  
1997 ◽  
Vol 22 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Anne M. Mayes ◽  
Sanat K. Kumar
Keyword(s):  
Statistical Mechanics ◽  
Chemical Modification ◽  
Surface Chemistry ◽  
First Principles ◽  
Surface Composition ◽  
Polymer Surface ◽  
Polymer Surfaces ◽  
Computing Power ◽  
Complex Chemical ◽  
Theoretical Approaches

The control of surface chemistry and topography has great technological relevance for numerous applications of polymers in textiles, adhesives, coatings, packaging, membranes, and biomedical implants. Conventionally, chemical modification of polymer surfaces has been achieved through kinetically governed practices that allow little control over the final surface composition or morphology. These chemically generated surfaces are also prone to reconstruction. Hence the development of inexpensive, scaleable routes to impart stable and more complex chemical functionality to polymer surfaces continues to be an active area of research. Apart from surface chemistry, the topography of a polymer surface often plays a determinant role in the adhesive, optical, and wetting characteristics of the surface. Consequently methods to produce surfaces of controlled texture are also of interest. Toward these goals, new, statistical, mechanics-based theoretical approaches, coupled with increased computing power, can now facilitate the first-principles design of polymer surfaces that are chemically and structurally “tailored” for a given application. In this article, we review some of the recent, significant developments in this area.

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