Sorption properties and temperature-dependent near-surface chemistry of the BaLi4 intermetallic compound

1999 ◽  
Vol 17 (5) ◽  
pp. 2696-2702
Author(s):  
R. M. Caloi ◽  
P. Manini ◽  
S. Vandré ◽  
E. Magnano ◽  
J. Kovac ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Surface Chemistry ◽  
Sorption Properties ◽  
Temperature Dependent ◽  
Near Surface

A unique magnesium-based 3D MOF with nanoscale cages and temperature dependent selective gas sorption properties

2013 ◽  
Vol 49 (17) ◽  
pp. 1753 ◽  
Author(s):  
Yong-Liang Huang ◽  
Yun-Nan Gong ◽  
Long Jiang ◽  
Tong-Bu Lu
Keyword(s):  
Sorption Properties ◽  
Gas Sorption ◽  
Temperature Dependent

A Surface Analytical Study of the Effects of Water and Oxygen on Tribological Behavior of DLC Films

2005 ◽  
Author(s):  
O. L. Eryilmaz ◽  
A. Erdemir ◽  
J. A. Johnson ◽  
N. Mehta ◽  
B. Prorok
Keyword(s):  
Surface Chemistry ◽  
Friction And Wear ◽  
Analytical Study ◽  
Tribological Behavior ◽  
Mechanistic Explanation ◽  
Sliding Contact ◽  
Diamond Like Carbon ◽  
Near Surface ◽  
X Ray ◽  
Contact Surfaces

In this study, we explored the effects of water and oxygen molecules on friction and wear of diamond-like carbon (DLC) films. Specifically, using Raman and x-ray photoelectron spectroscopies we attempted to analyze the near surface chemistry and microstructure of sliding contact surfaces and correlated these findings with changes in friction and wear of DLC films. Tribological tests were run in a ball-on-disk machine under 2 to 5 N loads and in dry and moist nitrogen and oxygen environments. Based on the tribological and surface analytical findings, a mechanistic explanation is provided for the high friction and wear of DLC in dry and humid oxygen environments.

The Relationship Between Near-Surface Mechanical Properties, Loading Rate And Surface Chemistry

1997 ◽  
Vol 505 ◽  
Author(s):  
A. B. Mann ◽  
P. C. Searson ◽  
J. B. Pethica ◽  
T. P. Weihs
Keyword(s):  
Mechanical Properties ◽  
Surface Chemistry ◽  
Tribological Properties ◽  
Mechanical Response ◽  
Loading Rate ◽  
Atomic Scale ◽  
Initial Contact ◽  
Surface Films ◽  
Near Surface ◽  
Mechanical And Tribological Properties

ABSTRACTThe presence of thin surface films and adsorbate layers on both metals and ceramics can cause dramatic changes in the mechanical response of the material. A similar, related, variation in tribological properties has also been observed. Though the importance of surface effects is well known and widely documented, the exact physical and chemical mechanisms that are operating remain poorly understood. The development of point probe techniques now permits the examination of mechanical and tribological properties on the same length scale as the surface films. Recently, the utilization of these testing techniques has provided a clear insight into the mechanical processes which are operating on the atomic scale. The nanoindentation results presented here show that the mechanical deformation of an individual nano-contact is a highly dynamic phenomena in which the tip-momentum on contact, as well as the loading rate during the indentation, dictate the observed mechanical properties of the material. These results indicate that the initiation of plastic deformation is dependent on the stability of atomic-size surface asperities which can be deformed irreversibly by the high stresses generated during the initial contact. Additionally, the generation of dislocations and the presence of discontinuities in the loading curve are shown to depend upon the loading rate. More significantly, it has been found that modifying the surface chemistry can cause dramatic changes in both the mode of deformation and the time-dependence of nano-scale mechanical properties. The principal conclusion that can be drawn is that the high stresses which operate over short distances make time and temperature dependent phenomena, such as diffusion and the dissipation of energy via phonons, of vital importance in determining the near-surface mechanical properties of a material. Such effects are further magnified in tribological processes where normal and tangential loading of the surface leads to the repeated making and breaking of nano-asperity contacts.

Surface chemistry and moisture sorption properties of wood coated with multifunctional alkoxysilanes by sol-gel process

2003 ◽  
Vol 88 (12) ◽  
pp. 2828-2841 ◽  
Author(s):  
Mandla A. Tshabalala ◽  
Peter Kingshott ◽  
Mark R. VanLandingham ◽  
David Plackett
Keyword(s):  
Surface Chemistry ◽  
Sol Gel ◽  
Moisture Sorption ◽  
Sorption Properties ◽  
Sol Gel Process

Temperature Dependence of Amorphization above 10K in the CuTi Intermetallic Compound Under Electron Irradiation

1986 ◽  
Vol 74 ◽  
Author(s):  
J. Koike ◽  
D. E. Oluzzi ◽  
M. Meshii ◽  
P. R. Okamoto
Keyword(s):  
Critical Temperature ◽  
Intermetallic Compound ◽  
Cluster Formation ◽  
Irradiation Temperature ◽  
Crystalline Compound ◽  
Temperature Dependent ◽  
Defect Clusters ◽  
Critical Dose ◽  
Increasing Temperature ◽  
Critical Temperature Tc

AbstractThe critical dose required to amorphize the crystalline compound CuTi during irradiation with 1 MeV electrons has been investigated from 10 to 288 K. The results show that above a critical temperature (Tc) of about 185 K, CuTi remains crystalline and only defect clusters are formed. Below Tc, amorphization occurs with no observable cluster formation. The critical dose for amorphization was found to be temperature dependent below Tc: as the irradiation temperature increases, a higher dose is required to induce amorphization. This observation supports the concept that Tc corresponds to the vacancy migration temperature. Below Tc, interstitial migration may contribute to the observed reduction in the amorphization rate with increasing temperature.

Comprehensive Quantification of Sorption Characteristics in Polymer Material of Thin Film Form

2011 ◽  
Author(s):  
Heejin Park ◽  
Ji-Hyuk Lim ◽  
Suk-Jin Ham ◽  
Bongtae Han
Keyword(s):  
Thin Film ◽  
Moisture Sorption ◽  
Moisture Diffusion ◽  
Least Square ◽  
Sorption Properties ◽  
Polymer Materials ◽  
Circuit Board ◽  
Temperature Dependent ◽  
Thin Film Form ◽  
Film Form

In this paper, the standard procedures for measuring moisture sorption properties of thin film form of polymer materials such as polyethylene terephthalate (PET) using thermo-gravimetry method and permeation method to characterize the moisture diffusion in polymer is presented. Analytical solution of moisture diffusion and FEA implementation using thermal-moisture analogy for comparison with measurements are presented, in which temperature dependent material properties are characterized. The measurement of permeability is used for validation of moisture diffusion characteristics. Nonlinear behavior of moisture diffusion dependent on concentration is investigated using a specimen having diffusion on half side and diffusivity constants are obtained by solving non-Fickian model and minimizing errors of least square with measurement. Application of characterizing moisture sorption properties to moisture effect on the interfacial layer in multi-layered printed circuit board (PCB) and estimation of relative humidity (RH) through permeation of moisture in hermetic sealing of crystal resonator are presented in this paper: i) The discrepancy of moisture concentration at the interlayer in multi-layered PCB was estimated as loading condition varies. ii) Moisture content through sealant based on temperature dependent permeability was estimated using mixture of ideal gases and vapor pressure.

scholarly journals Interaction of Nanodiamonds with Water: Impact of Surface Chemistry on Hydrophilicity, Aggregation and Electrical Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2740
Author(s):  
Pietro Aprà ◽  
Lorenzo Mino ◽  
Alfio Battiato ◽  
Paolo Olivero ◽  
Sofia Sturari ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Surface Chemistry ◽  
Water Adsorption ◽  
Electrical Conductance ◽  
Depth Information ◽  
Thermal Processes ◽  
Water Impact ◽  
Temperature Dependent ◽  
Research Fields ◽  
Influence Of Water

In recent decades, nanodiamonds (NDs) have earned increasing interest in a wide variety of research fields, thanks to their excellent mechanical, chemical, and optical properties, together with the possibility of easily tuning their surface chemistry for the desired purpose. According to the application context, it is essential to acquire an extensive understanding of their interaction with water in terms of hydrophilicity, environmental adsorption, stability in solution, and impact on electrical properties. In this paper, we report on a systematic study of the effects of reducing and oxidizing thermal processes on ND surface water adsorption. Both detonation and milled NDs were analyzed by combining different techniques. Temperature-dependent infrared spectroscopy was employed to study ND surface chemistry and water adsorption, while dynamic light scattering allowed the evaluation of their behavior in solution. The influence of water adsorption on their electrical properties was also investigated and correlated with structural and optical information obtained via Raman/photoluminescence spectroscopy. In general, higher oxygen-containing surfaces exhibited higher hydrophilicity, better stability in solution, and higher electrical conduction, although for the latter the surface graphitic contribution was also crucial. Our results provide in-depth information on the hydrophilicity of NDs in relation to their surface chemical and physical properties, by also evaluating the impacts on their aggregation and electrical conductance.

scholarly journals Siloxane adsorption on activated carbons: Role of the surface chemistry on sorption properties in humid atmosphere and regenerability issues

2019 ◽  
Vol 371 ◽  
pp. 821-832 ◽  
Author(s):  
Vu Tung Lam Tran ◽  
Patrick Gélin ◽  
Corinne Ferronato ◽  
Pascale Mascunan ◽  
Vladislav Rac ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Activated Carbons ◽  
Sorption Properties ◽  
Humid Atmosphere
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