Graphene oxide (GO), which is a monolayer of graphene with various oxidized groups, has wide application in materials technology, biomedicine, catalysis, as well as a surfactant. Due to it's amphiphilic nature GO can be dispersed in both water and organic solvents. This makes it a suitable carrier for isolation of hazardous chemicals such as dyes from industial waste water. The efficiency of graphene oxide as a carrier depends on pH [1] as well as the presence of different salts in solution [2].
MD simulations enable to understand the pH dependece of the interactions of different ions with GO surface on molecular level. The influence of ions to the surface charge of GO has been quantified by radial distribution function, which calculates the distribution of ions around a single molecule of GO. The observed interaction modes of ions with the surface of GO support experimental results from zeta potential measurements of graphene oxide in different salt solutions, as well as the efficiency in extraction of methyl blue from aqueous solutions [2].