Characteristics Of The Material Structure Evolution In Carbon Nanotubes

As known to all, since the particular one-dimensional advantages and the nanoscale structures make the fillers possess novel properties which are quite different from those of their bulk counterparts, filling carbon nanotube with chosen materials can lead to nanostructures with exciting new applications. The encapsulation of a wide array of materials, including metals, liquids and fullerenes, within carbon nanotube and the properties of the fillers have been discussed both theoretically and experimentally. Therefore, it is of great significance to figure out the interaction mechanism between the nanosize fillers and the carbon nanotube and further control the properties of these hybrid structures.In this work we have carried out systematic molecular dynamics simulation on the spontaneous encapsulation behavior of graphene nanoribbon and ion liquid into carbon nanotube and the phase transition of Fe melt in carbon nanotube, which is essential to the substantial potential applications for exploring new theories and functional devices.It has been observed for the first time that the graphene nanoribbon can enter the carbon nanotube and form helical configuration spontaneously. The van der Waals force traps the graphene nanoribbon in the carbon nanotube, while the formation of the graphene nanoribbon helix is attributed to the π-π stacking interaction between the graphene nanoribbon and carbon nanotube. During the whole encapsulating course, the decline of the potential energy in the whole system suggests that the helix-forming is a spontaneously phenomenon and the system is increasingly stable during this process. Three simulations on two graphene nanoribbons placed at different positions in the carbon nanotube are carried out to investigate the double-helical encapsulation feature of two graphene nanoribbon. A water cluster may be of great influence to the helical encapsulation process of the graphene nanoribbon into the carbon nanotube.The spontaneous encapsulation of1-Butyl-3-methylimidazolium Chloride ([Bmim][Cl]) into the single-walled carbon nanotubes can be attributed to the van der Waals attractive force, the hydrogen bonds and especially the π-π stacking effect. The [Bmim][Cl] molecules enter the carbon nanotubes possessing a larger diameter more rapidly, showing a interesting dependence on tube size. The high temperature is not beneficial to and even may disrupt the encapsulation of the [Bmim][Cl] molecules. It is also worth noting that the graphene nanoribbon entering the carbon nanotubes would have an extremely different effect on this encapsulation process from that wrapping on the outer surface. Furthermore, the [Bmim][Cl] molecules can assist the water transport in the carbon nanotubes by expelling water molecules out of the carbon nanotubes.Coaxial multi-layered structure is obtained when the Fe melt confined in the single-walled carbon nanotube (SWCNT) undergoes a rapid cooling. Owing to the inductive effect of the SWCNT, precursors of the long-range order (LRO) have are generated in the confined Fe melt and finally been converted into local crystalline structures in the glassy Fe. A memory property has also been observed during the repeated phase transition process. Furthermore, the study of the size effect of tube diameter illustrates that the increasing diameter of the carbon tube is detrimental to the formation of local crystalline structures in nanoscale confinement.The above mentioned discoveries are of great significance in the exploration of the properties of the carbon nanotube hybrid system. Some results may expand the applications of these composites in extensive fields involving medicine, chemistry, and biology and even fuel cells.