Molecular dynamics simulations of graphene oxide frameworks

We use quantum mechanical calculations to develop a full set of force field parameters in order to perform molecular dynamics simulations to understand and optimize the molecular storage properties inside graphene oxide frameworks (GOFs). A set of boron-related parameters for commonly used empirical force fields is determined to describe the nonbonded and bonded interactions between linear boronic acid linkers and graphene sheets of GOF materials. The transferability of the parameters is discussed and their validity is quantified by comparing quantum mechanical and molecular mechanical structural and vibrational properties. The application of the model to the dynamics of water inside the GOFs reveals significant variations in structural flexibility depending on the linker density, which is shown to be usable as a tuning parameter for desired diffusion properties.