Advancing the understanding of self-assembled monolayers

Because of their strong chemical adsorption onto metal surfaces, self-assembled monolayers (SAMs) are used in crystal nucleation, a first step in developing new materials. However, the ultrathin substrates have been extremely difficult to model and therefore optimize.

Souza et al. developed a method for creating highly accurate computer models of these nanomaterials that can be applied for any molecule-surface combination.

“SAMs organize themselves into incredibly precise patterns — almost like molecular mosaics — just by dipping a surface into a solution,” said author Felipe Fantuzzi. “They’re easy to make, but their properties are surprisingly complex and still not fully understood after nearly 80 years of study.”

The team used advanced software to build a nanoscale, all-atom computer model and examined how the parameters of the force field, which describe potential atomic energy in molecular simulations, affect SAM stability and structural properties in relation to two different gold surfaces.

“The model helps explain why certain structures form, by revealing how different interactions contribute to the final arrangement,” said author Cauê Souza. “This means we’re not just creating a simulation tool — we’re advancing the fundamental understanding of how SAMs behave.”

The researchers were initially motivated to simulate a new, energy-efficient nanofabrication method involving SAMs — photo-assisted chemical vapor deposition — that can deposit metals at room temperature using light instead of heat, which is ideal for delicate materials like organic thin films used in solar cells. Their work, however, became more widely applicable.

“Looking ahead, our approach could be used to study far more complex SAM systems and help guide design of new technologies, including more sensitive chemical detectors; faster and more flexible electronics; cleaner industrial processes; and innovative medical devices,” said Souza.

Source: “A refined atomistic model of functionalized self-assembled monolayers on gold: Assessment of force field parameters,” by Cauê P. Souza, Alexey V. Verkhovtsev, Nigel J. Mason, Andrey V. Solov’yov, and Felipe Fantuzzi, Journal of Chemical Physics (2025). The article can be accessed at https://10.1063/5.0274290 .

This paper is part of the 2025 JCP Emerging Investigators Special Collection, learn more here .