Related Experiment Video
Updated: Jan 30, 2026
11:54
Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles
Published on: June 25, 2018
10.8K
Evolution of ligand-capped nanoparticle multilayers toward a near unique thickness
1Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India. satyajit.hazra@saha.ac.in.
Soft Matter
|February 1, 2019
Summary
Thiol-capped gold nanoparticle (AuNP) multilayers on silicon become unstable, shrinking to a unique thickness (NUT) of about 6 nm due to thermal energy and surface energy changes. This self-organization forms a stable layer, revealing insights into nanoparticle interactions.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Science
Background:
- Thiol-capped gold nanoparticles (AuNPs) are used in bottom-up fabrication.
- Controlling multilayer structures on substrates is challenging.
- Langmuir-Schaefer (LS) deposition is a method for creating thin films.
Purpose of the Study:
- Investigate the structural evolution of AuNP multilayers on silicon.
- Understand the instability and self-organization processes.
- Characterize the formation of a near unique thickness (NUT) layer.
Main Methods:
- Utilized complementary grazing incidence X-ray scattering techniques.
- Employed Langmuir-Schaefer (LS) deposition for multilayer formation.
- Studied AuNP multilayers on a hydrogen-passivated silicon substrate.
Main Results:
- Fractional coverage AuNP multilayers exhibit instability under ambient conditions.
- Layer thickness decreases over time, saturating at a near unique thickness (NUT ≈ 6 nm).
- Thermodynamic instability drives AuNP diffusion and reorganization into a stable NUT-layer.
Conclusions:
- The formation of a NUT-layer is a distinctive, thermodynamically driven process.
- Hydrophobic-hydrophobic interactions promote substrate attraction, while repulsion and thermal fluctuations are short-range.
- Understanding these interactions is key for designing 3D nanostructures.
Related Concept Videos
02:55The Evidence for Evolution
48.0K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
48.0K
01:18Other Unique Bacteria
436
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic...
436
01:54Convergent Evolution
32.8K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
32.8K
01:16Second Uniqueness Theorem
2.6K
Consider a region consisting of several individual conductors with a definite charge density in the region between these conductors. The second uniqueness theorem states that if the total charge on each conductor and the charge density in the in-between region are known, then the electric field can be uniquely determined.
In contrast, consider that the electric field is non-unique and apply Gauss's law in divergence form in the region between the conductors and the integral form to the surface...
In contrast, consider that the electric field is non-unique and apply Gauss's law in divergence form in the region between the conductors and the integral form to the surface...
2.6K
02:40Ligand Binding Sites
15.0K
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
15.0K
02:51Metal-Ligand Bonds
24.2K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
24.2K