Martini 3 coarse-grained models for carbon nanomaterials

The Martini model is a coarse-grained force field allowing simulations of biomolecular systems as well as a range of materials, including different types of nanomaterials of technological interest. Recently, a new version of the force field (version 3) has been released, that includes new parameters for lipids, proteins, carbohydrates, and a number of small molecules, but not yet carbon nanomaterials. Here, we present new Martini models for three major types of carbon nanomaterials: fullerene, carbon nanotubes, and graphene. The new models were parameterized within the Martini 3 framework, and reproduce semi-quantitatively a range of properties for each material. In particular, the model of fullerene yields excellent solid-state properties and good properties in solution, including correct trends in partitioning between different solvents and realistic translocation across lipid membranes. The models of carbon nanotubes reproduce the atomistic behavior of nanotube porins spanning lipid bilayers. The model of graphene reproduces structural and elastic properties, as well as trends in experimental adsorption enthalpies of organic molecules. All new models can be used in large-scale simulations to study the interaction with the wide variety of molecules already available in the Martini 3 force field, including biomolecular and synthetic systems.