Department of Chemistry, Nanoscale Sciences and Technology Institute, Wonkwang University, Iksan, Jeonbuk 54538, Korea.
Max Planck POSTECH Center for Complex Phase of Materials, Pohang University of Science and Technology, Pohang 37673, Korea.
Int J Mol Sci. 2021 Apr 10;22(8):3929. doi: 10.3390/ijms22083929.
In previously reported experimental studies, a yield of double-walled carbon nanotubes (DWCNTs) at C@Single-walled carbon nanotubes (SWCNTs) is higher than C@SWCNTs due to the higher sensitivity to photolysis of the former. From the perspective of pyrolysis dynamics, we would like to understand whether C@SWCNT is more sensitive to thermal decomposition than C@SWCNT, and the starting point of DWCNT formation, which can be obtained through the decomposition fragmentation of the nanopeapods, which appears in the early stages. We have studied the fragmentation of C@SWCNT nanopeapods, using molecular dynamics simulations together with the empirical tight-binding total energy calculation method. We got the snapshots of the fragmentation structure of carbon nano-peapods (CNPs) composed of SWCNT and C fullerene molecules and the geometric spatial positioning structure of C within the SWCNT as a function of dynamics time (for 2 picoseconds) at the temperatures of 4000 K, 5000 K, and 6000 K. In conclusion, the scenario in which C@SWCNT transforms to a DWCNT would be followed by the fragmentation of C, after C, and the SWCNT have been chemically bonding in the early stages. The relative stability of fullerenes in CNPs could be reversed, compared to the ranking of the relative stability of the encapsulated molecules themselves.
在之前报道的实验研究中,由于前者对光解的敏感性更高,因此双壁碳纳米管 (DWCNT) 的产率高于 C@单壁碳纳米管 (SWCNT)。从热解动力学的角度来看,我们希望了解 C@SWCNT 是否比 C@SWCNT 更容易发生热分解,以及 DWCNT 形成的起点,这可以通过纳米豆荚的分解碎片来获得,而这种纳米豆荚在早期就会出现。我们使用分子动力学模拟和经验紧束缚总能量计算方法研究了 C@SWCNT 纳米豆荚的碎裂。我们得到了由 SWCNT 和 C 富勒烯分子组成的碳纳米豆荚 (CnP) 的碎裂结构的快照,以及 C 在 SWCNT 内的几何空间定位结构作为动力学时间(2 皮秒)的函数在 4000 K、5000 K 和 6000 K 的温度下。总之,在早期 C 和 SWCNT 发生化学结合之后,C@SWCNT 转化为 DWCNT 的情景将遵循 C 的碎裂。与封装分子自身的相对稳定性排序相比,CnP 中富勒烯的相对稳定性可能会发生逆转。