Structure and Dynamics of Water at Carbon-Based Interfaces

Abstract

Water structure and dynamics are affected by the presence of a nearby interface. Here, first we review recent results by molecular dynamics simulations about the effect of different carbon-based materials, including armchair carbon nanotubes and a variety of graphene sheets-flat and with corrugation-on water structure and dynamics. We discuss the calculations of binding energies, hydrogen bond distributions, water's diffusion coefficients and their relation with surface's geometries at different thermodynamical conditions. Next, we present new results of the crystallization and dynamics of water in a rigid graphene sieve. In particular, we show that the diffusion of water confined between parallel walls depends on the plate distance in a non-monotonic way and is related to the water structuring, crystallization, re-melting and evaporation for decreasing inter-plate distance. Our results could be relevant in those applications where water is in contact with nanostructured carbon materials at ambient or cryogenic temperatures, as in man-made superhydrophobic materials or filtration membranes, or in techniques that take advantage of hydrated graphene interfaces, as in aqueous electron cryomicroscopy for the analysis of proteins adsorbed on graphene.

Molecular dynamics study of nanoconfined TIP4P/2005 water: how confinement and temperature affect diffusion and viscosity

“…In the same panel we also report the result from Ref. [49] obtained for TIP4P/2005 water in a more stringent confinement. The discrepancy with respect to our results might be due to the fact that water in Ref.…”

“…In a second paper, the same authors have considered smaller tubes and rationalized the differences in terms of viscous entrance effects controlled by the viscosity of the water model at the entrance of the tube. [61] Among recent simulation works on confined TIP4P/2005 water under equilibrium conditions, one can mention the work of Köhler et al [48] and Marti et al [49] Both groups considered this model either confined inside or outside CNTs with hydrophobic or hydrophilic walls. Different diameters were considered and their effect on structural or transport properties were analyzed for some selected thermodynamic conditions.…”

Hydrogen bond correlated percolation in a supercooled water monolayer as a hallmark of the critical region

“…[50] by Sastry, Debenedetti, Sciortino and Stanley. The monolayer is kept between parallel walls at sub-nanometer distance, h = 0.5 nm, with purely repulsive (excluded volume) hydrophobic interaction, allowing deep supercooling without crystallization, consistent with simulations and experiments [87,88]. We consider the model in the Gibbs ensemble, keeping the number N of molecules, the pressure P and the temperature T fixed.…”

Dynamic Properties of Water Confined in Graphene-Based Membrane: A Classical Molecular Dynamics Simulation Study

“…The stacked graphene membrane was composed of four layers of graphene sheets, and each layer was composed of four rectangular graphenes with the dimension of~20 Å ×~20 Å ( Figure 1B). The distance between sheets in the same layer (d 1 ) and the distance between layers (d 2 ) was set as 7 Å, which is the minimum distance water molecules can penetrate [33]. Since the dimension of the sheets and the distance between them were fixed, the dimension of the periodic simulation box was also determined: Figure 1C,D).…”