Wettability of azobenzene self-assembled monolayers

Area of Science:

• Surface Science and Nanotechnology
• Computational Chemistry and Materials Science

Background:

• Azobenzene self-assembled monolayers (SAMs) exhibit distinct cis and trans isomeric forms.
• Understanding the wettability of these SAMs is crucial for applications in responsive materials and surface engineering.

Purpose of the Study:

• To investigate the wettability properties of azobenzene SAMs in both trans and cis configurations.
• To provide an atomistic explanation for the observed differences in wettability between the two isomers.

Main Methods:

• Classical Molecular Dynamics (MD) simulations were employed using validated assembly structures.
• A dedicated force field was utilized to describe the azobenzene SAMs.
• Contact angles were calculated using two distinct methodologies: Young's equation and geometrical models.

Main Results:

• Consistent wettability descriptions were obtained, aligning with available experimental data.
• The simulations provided an atomistic perspective on the initial water layers at the solvent-SAM interface.
• A clear rationalization of the wettability differences between cis- and trans-SAMs was achieved.

Conclusions:

• Molecular Dynamics simulations effectively capture the wettability behavior of azobenzene SAMs.
• The study elucidates the molecular origins of wettability differences based on azobenzene isomerism.
• Findings support the use of MD simulations for predicting and understanding surface properties of functional SAMs.