Studies and comparison of the liquid adsorption behavior and surface properties of single- and multiwall carbon nanotubes by capillary rise method

The liquid adsorption behaviors and surface properties of single- (SWCNT) and multiwall (MWCNT) carbon nanotubes were studied and compared by the capillary rise method. It was found that these CNTs both adsorbed the diiodomethane greatly as compared with other liquids, e.g. water, formamide and hexane, and the reason is due to the total surface free energy of these CNTs both dominated by the Lifshitz–van der Waals interactions component, especially the SWCNTs at about 95%. Comparison further indicated that the SWCNT adsorbed the polar liquid greatly due to stronger in the Lewis base component and the MWCNT adsorbed the non-polar liquid greatly due to stronger in the Lewis acid component. The total surface free energy of SWCNT is about 50 mN/m slight greater than that of the MWCNT.