Related Experiment Video
Updated: Feb 9, 2026
06:56
Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis
Published on: September 22, 2023
1.7K
Comparisons of Analytical Approaches for Determining Shell Thicknesses of Core-Shell Nanoparticles by X-ray
C J Powell1, W S M Werner2, H Kalbe2
1Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8370, United States.
Summary
Determining nanoparticle shell thickness using X-ray photoelectron spectroscopy (XPS) is assessed. An empirical equation showed good accuracy, while elastic scattering effects were minimal for organic shells on gold cores.
Area of Science:
- Materials Science
- Surface Science
- Nanotechnology
Background:
- Accurate characterization of core-shell nanoparticles (NPs) is crucial for understanding their properties.
- X-ray photoelectron spectroscopy (XPS) is a powerful surface-sensitive technique for elemental analysis and chemical state determination.
- Quantifying shell thickness in core-shell NPs using XPS requires reliable methodologies.
Purpose of the Study:
- To evaluate two distinct approaches for determining the shell thicknesses of core-shell NPs via XPS.
- To validate an empirical equation for shell thickness determination.
- To investigate the impact of elastic scattering on photoelectron peak intensities in various core-shell NP systems.
Main Methods:
- Simulations of photoelectron peak intensities were performed for diverse core-shell NP compositions (Au/C, C/Au, Cu/Al, Al/Cu).
- The study assessed shell thickness accuracy using an empirical equation developed by Shard.
- Elastic scattering effects were systematically evaluated by comparing simulations with and without elastic scattering enabled.
Main Results:
- The Shard empirical equation provided shell thickness values with typically better than 10% agreement with actual thicknesses.
- For Au-core/C-shell NPs, elastic scattering effects on intensity ratios were generally less than 10%, validating its neglect in models for organic ligands on gold.
- Elastic scattering effects were significantly more pronounced for C-core/Au-shell, Al-core/Cu-shell, and Cu-core/Al-shell NPs, showing dependencies on core diameter and shell thickness.
Conclusions:
- The Shard equation is a reliable method for determining shell thicknesses of core-shell NPs using XPS.
- Elastic scattering can be neglected for organic shells on gold cores but must be considered for other metal-metal core-shell systems.
- These findings provide guidance for accurate XPS analysis of core-shell nanostructures.
More Related Videos
Related Concept Videos
02:18X-ray Crystallography
26.2K
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
26.2K
02:10The Nucleosome Core Particle
14.5K
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
14.5K
01:12The Nucleosome Core Particle
2.4K
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
2.4K
02:57The Sense of Self: Reflected Self-Appraisal and Social Comparison
56.1K
According to Charles Cooley, we base our image on what we think other people see (Cooley 1902). We imagine how we must appear to others, then react to this speculation. We don certain clothes, prepare our hair in a particular manner, wear makeup, use cologne, and the like—all with the notion that our presentation of ourselves is going to affect how others perceive us. We expect a certain reaction, and, if lucky, we get the one we desire and feel good about it. But more than that, Cooley...
56.1K
01:22Bioavailability Enhancement: Determination and Conceptual Approaches in Overcoming Bioavailability Problems
212
Body:Bioavailability is a critical pharmacological concept that measures the extent and rate at which an active drug ingredient or therapeutic moiety enters the systemic circulation, remaining unchanged. It's a pivotal factor in determining a drug's efficacy and safety.The Biopharmaceutics Classification System (BCS) plays an essential role in drug development by categorizing drugs into four classes based on their solubility and permeability. This classification aids in understanding drug...
212
01:21Development of Analytical Methods
2.3K
An analytical methodology can be divided into four sequential steps: technique, method, procedure, and protocol. A technique is a scientific principle that rationalizes a specific phenomenon through chemical measurements. Adapting a technique for analyzing a sample of interest is termed a method. The procedure outlines the directions for performing the analysis via an analytical method. The protocol is the detailed guidelines on the procedure, which should be strictly followed to obtain the...
2.3K