Atom probe tomography measurements of self-assembled monolayers of 1-octadecanethiol on platinum tips were performed and their fragmentation behavior under the influence of different laser powers was investigated. The carbon backbone evaporates in the form of small hydrocarbon fragments consisting of one to four carbon atoms, while sulfur evaporates exclusively as single ions. The carbon molecules evaporate at very low fields of 5.9 V/nm, while S requires a considerably higher evaporation field of 23.4 V/nm. With increasing laser power, a weak, but noticeable trend toward larger fragment sizes is observed. No hydrocarbon fragments containing S are detected, indicating that a strong S–Pt bond has formed. The observed surface coverage of S fits well with literature values and is higher for (111)-oriented samples than for (200).
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http://dx.doi.org/10.1017/S1431927621012654 | DOI Listing |
Phys Chem Chem Phys
September 2020
Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk 630090, Russia.
MIL-53 (Al) is an example of a MOF with a flexible framework featuring a broad range of applications such as hydrocarbon adsorption, separation and catalysis. Such processes are strongly influenced by the flexibility of the framework and thus require monitoring of the interrelation between the guest dynamics and framework breathing events. Here, we demonstrate that breathing of the framework can be monitored by probing the isobutane guest dynamics with H solid-state nuclear magnetic resonance (H NMR).
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506, United States.
Metal flux methods are excellent for synthesizing high-quality hexagonal boron nitride (hBN) crystals, but the atomic mechanisms of hBN nucleation and growth in these systems are poorly understood and difficult to probe experimentally. Here, we harness classical reactive molecular dynamics (ReaxFF) to unravel the mechanisms of hBN synthesis from liquid nickel solvent over time scales up to 30 ns. These simulations mimic experimental conditions by including relatively large liquid nickel slabs containing dissolved boron and a molecular nitrogen gas phase.
View Article and Find Full Text PDFUltramicroscopy
January 2025
Christian Doppler Laboratory for Sustainable Hard Coatings at the Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria.
The impact of the laser wavelength on accuracy in elemental composition analysis in atom probe tomography (APT) was investigated. Three different commercial atom probe systems - LEAP 3000X HR, LEAP 5000 XR, and LEAP 6000 XR - were systematically compared for a TiN model coating studying the effect of shorter laser wavelengths, especially in the deep ultraviolet (DUV) range, on the evaporation behavior. The findings demonstrate that the use of shorter wavelengths enhances the accuracy in elemental composition, while maintaining similar electric field strengths.
View Article and Find Full Text PDFAnal Chem
January 2025
Institute of Physical Science and Information Technology, Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui 230601, China.
Real-time monitoring of the dynamics of cytosolic RNA-protein condensates, termed stress granules (SGs), is vital for understanding their biological roles in stress response and related disease treatment but is challenging due to the lack of simple and accurate methods. Compared with protein visualization that requires complex transfection procedures, direct RNA labeling offers an ideal alternative for tracking SG dynamics in living cells. Here, we propose a novel molecular design strategy to construct a near-infrared RNA-specific fluorescent probe () for tracking SGs in living cells.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Materials Science and Engineering, Feng Chia University, Taichung City, 40724, Taiwan.
The unique optical properties of perovskite quantum dots (PQDs), particularly the tunable photoluminescence (PL) across the visible spectrum, make them a promising tool for chlorinated detection. However, the correlation between the fluorescence emission shift behavior and the interface of phase transformation in PQDs has not been thoroughly explored. In this study, we synthesized CsPbBr PQDs via the hot-injection method and demonstrated their ability to detect chlorinated volatile compounds such as HCl and NaOCl through a halide exchange process between the PQDs' solid thin film and the chlorinated vapor phase.
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