Title : Using electric field to regulate the flow of nano-confined liquid
Abstract:
In recent years, membranes, porous polymers and carbon nanotube arrays with nano-channels have shown great potential in solar desalination. Water will exhibit distinctive mass transfer behavior in the nano channels of these materials under the temperature difference caused by solar energy. It is of great significance to enhance the thermophoresis of nanoscale confined liquid for improving the efficiency of seawater desalination. Unfortunately, it is not clear how to enhance mass transfer through non-contact method at present, but it is very expected in technology. In this work, we propose a feasible strategy to enhance the thermophoresis of confined nano-liquid via using external electric field. Moreover, this strategy is demonstrated by a striking case, namely the electric field-intensified thermophoresis of the confined nano-liquid within carbon nanotube, with the aid of molecular dynamics simulation. The interfacial water molecules undergo a configuration transition from the disorder-like to the ordered network-like under the directional electric field-induced hydrogen bond interactions. The electric field also influences the moving parameters of water molecules in CNT significantly. The friction coefficient λ decreases with the increase of electric field intensity E. The order parameter of water molecule movement increases about twice. As a result, thermophoresis depicts a regular movement under electric field and the velocity increase as high as 99% is also achieved. This work illustrates a great promising potential in seawater desalination, cellular uptake and drug carrier, and nanofiltration membranes.
Audience take Away:
- Recognize the potential application of Molecular Dynamic simulation technology in green nanotechnology;
- Understand the research status of the confined water mass transfer in nanoscale;
- Understand the mechanism of mass transfer regulation of confined water using electric fields. And provide some opinions different from previous researchers.