Transportation Of Confined Water

Graphene and carbon nanotubes have natural nanochannels,and water confined in these nanochannels has extremely low resistance.Therefore,carbon-based nanomaterials such as graphene and carbon nanotubes have become the ideal materials for studying the transport of water under constrained systems.It has potential application value in seawater desalination,life sciences and other fields.Due the small size of nanochannels,it is difficult to obtain detailed information on the flow of water in experimental studies.In this paper,molecular dynamics simulation was used to study the transport of water in nanochannels.(1)The interlayer water confined in the 0.65 nm graphene slit pore spontaneously form square ice structures.When the pressure is about 15.0-55.0Mpa,.the pressure has little influence on the structure of the ice.But the effect of pressure on the ice transport in the graphene nanochannels is essentially.The friction coefficient between the wall and the water increases with the increasing of pressure.Moreover,the structure of water and the structure of the interface between the wall and the water is investigated.the results show that the interfacial potential energy servers a essential role.(2)we study the interfacial friction of water in nanochannels with various configuration(two-dimensional graphene nanochannels,triangle nanochannels,quadrilateral nanochannels,hexagonal nanochannels,octagonal nanochannels and circular nanochannels).our simulation results show that the friction coefficient is related to the configuration of the nanochannels.When the configuration of nanochannels appear closer to the circle,the friction coefficient between the wall and the water is smaller.So we think that the configuration of solid wall serves as an effective route to control the water transport in nanochannels.The molecular mechanisms of the configuration effect on the transport are also studied.We find that the change of corrugation of the solid-liquid interaction potential makes the most important contribution to the change of the friction coefficient.