A new effect of the amorphous component of periodic crystallization in the surface layers of coatings during hydroxyapatite (HA) plasma spraying is revealed. The effect is caused by significant temperature increases of surface layers due to plasma heating in the process of coating. Under prevalent spraying conditions, the crystallite sizes of the crystallite phase are considerably less than those in dense HA. These non-equilibrium phases crystallize consistently and, as a result, in the surface layers HA crystallites emerge and grow. This leads to oscillating type dependences of crystallite size and crystallinity on coating thickness.
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http://dx.doi.org/10.1016/0142-9612(93)90158-x | DOI Listing |
Nanoscale
January 2025
Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
The highly anisotropic and nonadditive nature of nanoparticle surfaces restricts their characterization by limited types of techniques that can reach atomic or molecular resolution. While small-angle neutron scattering (SANS) is a unique tool for analyzing complex systems, it has been traditionally considered a low-resolution method due to its limited scattering vector range and wide wavelength spread. In this article, we present a novel perspective on SANS by showcasing its exceptional capability to provide molecular-level insights into nanoparticle interfaces.
View Article and Find Full Text PDFACS Catal
January 2025
Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague 8, Czech Republic.
Achieving the optimal balance between cost-efficiency and stability of oxygen reduction reaction (ORR) catalysts is currently among the key research focuses aiming at reaching a broader implementation of proton-exchange membrane fuel cells (PEMFCs). To address this challenge, we combine two well-established strategies to enhance both activity and stability of platinum-based ORR catalysts. Specifically, we prepare ternary PtNi-Au alloys, where each alloying element plays a distinct role: Ni reduces costs and boosts ORR activity, while Au enhances stability.
View Article and Find Full Text PDFCommun Mater
January 2025
Physik-Institut, Universität Zürich, Zürich, Switzerland.
The discovery of unconventional superconductivity often triggers significant interest in associated electronic and structural symmetry breaking phenomena. For the infinite-layer nickelates, structural allotropes are investigated intensively. Here, using high-energy grazing-incidence x-ray diffraction, we demonstrate how in-situ temperature annealing of the infinite-layer nickelate PrNiO ( ≈ 0) induces a giant superlattice structure.
View Article and Find Full Text PDFTurk J Chem
November 2024
Research Center in Industrial Technologies CRTI, Algiers, Algeria.
A novel silica-based material (SBM), synthesized from chemically-, thermally-, and mechanically-treated blast furnace slag (TBFS), was examined for its batch-mode lead adsorption capacity based on various parameters. Physicochemical examinations revealed that the formulation of the new SBM consisted mainly of silica, which represented 81.79% of its total composition.
View Article and Find Full Text PDFLab Chip
January 2025
Institute of Translational Medicine, Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland.
Proteases, an important class of enzymes that cleave proteins and peptides, carry a wealth of potentially useful information. Devices to enable routine and cost effective measurement of their activity could find frequent use in clinical settings for medical diagnostics, as well as some industrial contexts such as detecting on-line biological contamination. In particular, devices that make use of readouts involving magnetic particles may offer distinct advantages for continuous sensing because material they release can be magnetically captured downstream and their readout is insensitive to optical properties of the sample.
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