Striped gold nanoparticles: New insights from molecular dynamics simulations

Area of Science:

• Surface Science
• Nanotechnology
• Computational Chemistry

Background:

• Mixed self-assembled monolayers (SAMs) on gold nanoparticles (AuNPs) exhibit complex structural and hydration behaviors.
• Previous work established that thiol bending in SAMs is influenced by arrangement and terminal groups, affecting SAM properties.

Purpose of the Study:

• To investigate the effect of increasing stripe thickness on thiol bending in mixed SAMs of equal and unequal alkyl thiol lengths on AuNPs.
• To determine how stripe thickness influences the structural morphology and hydration of these SAMs.

Main Methods:

• Atomistic simulations were employed to model mixed self-assembled monolayers (SAMs) with varying stripe thicknesses.
• Analysis focused on structural properties, thiol bending, and hydration characteristics of SAMs on AuNPs.

Main Results:

• Stripe thickness significantly affects the structural and hydration properties of SAMs composed of unequal-length alkyl thiols.
• For SAMs with equal-length alkyl thiols, stripe thickness showed no significant impact on structural and hydration properties.
• The stability of the stripe configuration is contingent upon alkyl chain length, the difference in chain lengths within the mixture, and solvent characteristics.

Conclusions:

• Unequal alkyl chain lengths in mixed SAMs are crucial for stripe thickness to influence structural and hydration properties.
• The findings provide insights into the stability and behavior of mixed SAMs for applications in nanotechnology and surface science.