The Hindering Effect of the Electric Double Layer During the Retraction of the Inner Wall of a DWCNT

Compared with other carbon nanomaterials, carbon nanotubes are favored by researchers due to their unique geometric structure and amazing properties, one of which is the weak van der Waals force between the walls of double-walled carbon nanotubes (DWCNT). This property makes the sliding, rotation or screwlike motion of the inner wall relative to the outer wall can easily be implemented. However, most of the existing nanodevices based on this property can only work in vacuum or atmospheric environments, few of them can work in ionic solution. In present study, the ion concentration and ion mobility around a charged single-walled nanotube (SWCNT) which is immersed in KCL solution with the concentration of 2M was first analyzed. And the ion concentration distribution of Cl− and K+ on the XOY cross-section was plotted. The thickness of the electric double layer is about 5Å. The MD simulation results clearly show that the electric double layer generated on the inner wall of DWCNT can hinder the retraction of the inner wall relative to the outer wall.