1. Transition of Ionic Liquid [bmim][PF6] from Liquid to High-Melting-Point Crystal When Confined in Multiwalled Carbon Nanotubes

2. Physical Properties of the Ionic Liquids
(1)They are good solvents for a wide
range of both inorganic and organic
materials
(2)They are often composed of poorly
coordinating ions, so they have the
potential to be highly polar yet
noncoordinating solvents.
(3)polar alternative for two-phase
systems
(4)Ionic liquids are nonvolatile,hence
they may be used in high-vacuum
(1)they are used in
huge amounts and
(2)they are usually volatile liquids that
are difficult to contain.
Welton, T. Chem. Rev. 1999, 99,

3. Crystallization of Low-Melting Ionic Liquids
collected at -100 oC
Winterton, N. et. al. J. Am. Chem. Soc. 2005, 127,

4. Ice Nanotubes Inside Carbon Nanotubes
Koga, K. et. al. Nature. 2001, 6,

5. Impregnated Nanotubes with IL

6. Synthesis for IL@MWNTs

7. Figure 1. TEM images of opened MWNTs (a), (c), and HRTEM image of a small section of an individual tube of (d). (Inset) Electron
diffraction of a selected area of an individual nanotube filled with [bmim][PF6].

8. X-ray Diffraction Pattern

9. Figure 2. DSC heating curves for MWNTs (a), [bmim][PF6] (b),IL@MWNTs
(c), and (d) at a scan rate of 10 °C/min.

10. Conclusions The author demonstrated for the first time the
crystallization behavior of IL inside MWNTs, resulting in the formation of a stable, polymorphous crystal possessing a melting point of above 200 °C.
Not only provide a good addition to the development of new types of CNT-based composites, but they also are helpful for the understanding of phase transitions of dimensionally confined environments.