Related Experiment Video
Updated: Apr 21, 2026
10:09
Synthesis and Characterization of Amphiphilic Gold Nanoparticles
Published on: July 2, 2019
17.3K
Fluctuation-driven anisotropy in effective pair interactions between nanoparticles: thiolated gold nanoparticles in
B Shadrack Jabes1, Hari O S Yadav1, Sanat K Kumar2
1Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016, India.
The Journal of Chemical Physics
|October 24, 2014
Summary
Ligand shell fluctuations create anisotropic interactions for densely packed gold nanoparticles. This anisotropy, influenced by ligand length and solvent, is crucial for understanding nanoparticle self-assembly.
Area of Science:
- Nanotechnology
- Materials Science
- Physical Chemistry
Background:
- Ligand shell fluctuations induce anisotropy in nanoparticle interactions.
- Previous studies focused on low grafting densities.
Purpose of the Study:
- Examine fluctuation-driven anisotropy in densely passivated gold nanocrystals.
- Investigate anisotropy for gold nanocrystals capped by alkylthiols in vacuum and ethane solvent.
Main Methods:
- Quantify anisotropy using an angle-dependent correction to the isotropic potential of mean force (PMF).
- Analyze gold nanocrystals densely passivated with short alkylthiol ligands.
Main Results:
- Anisotropy is distance-dependent, affected by ligand interdigitation and expulsion.
- Significant anisotropy observed for alkylthiol-coated gold nanoparticles, especially with longer chains and good solvent conditions.
Conclusions:
- Isotropic potentials are insufficient for describing nanoparticle thermodynamics and assembly in dense regimes.
- Anisotropic and many-body effects are necessary for accurate modeling.
- Findings offer insights into nanoparticle self-assembly at varying grafting densities, solvent qualities, and interfaces.
Related Concept Videos
01:27π Electron Effects on Chemical Shift: Overview
1.5K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.5K
04:01VSEPR Theory and the Effect of Lone Pairs
39.9K
Effect of Lone Pairs of Electrons on Molecule Geometry
39.9K
01:27Inductive Effects on Chemical Shift: Overview
2.3K
The protons in unsubstituted alkanes are strongly shielded with chemical shifts below 1.8 ppm. Methine, methylene, and methyl protons appear at approximately 1.7, 1.2 and 0.7 ppm, while the proton signal from methane appears at 0.23 ppm. An electronegative substituent, such as chlorine, withdraws the electron density from the protons, increasing their chemical shift. Progressive substitution of the hydrogens in methane by chlorine shifts the proton signals increasingly downfield, to 3.05 ppm in...
2.3K