Development of non-bonded interaction parameters between graphene and water using particle swarm optimization

Area of Science:

• Computational chemistry and materials science.
• Interfacial phenomena and molecular dynamics simulations.

Background:

• Accurate modeling of graphene-water interactions is crucial for understanding interfacial properties.
• Existing atomistic water models require refined parameters for interaction with graphene surfaces.

Purpose of the Study:

• To develop new Lennard-Jones parameters for atomistic graphene models interacting with five common all-atom water models.
• To optimize these parameters using particle swarm optimization (PSO) to match experimental contact angles.
• To investigate the structural and dynamic properties of water at the graphene-water interface.

Main Methods:

• Development and optimization of Lennard-Jones parameters using particle swarm optimization (PSO).
• Atomistic molecular dynamics simulations of water droplets on graphene.
• Analysis of water molecule orientation, hydrogen bonding, and vibrational spectra.

Main Results:

• Optimized parameters successfully reproduced macroscopic contact angles.
• Simulations showed preferential orientation of water molecules at the graphene-water interface.
• Analysis revealed distinct hydrogen bonding patterns and water cluster formation at air-water and graphene-water interfaces.
• Vibrational spectra indicated structural changes and weaker hydrogen bonding in water droplets.

Conclusions:

• The developed parameters provide a more accurate description of graphene-water interactions.
• Water exhibits unique structural and dynamic behaviors at interfaces, influencing its properties.
• These findings contribute to a better understanding of water behavior in confined environments and at solid-liquid interfaces.