Decoding Structural Complexity In Fishbone-type Carbon Nanofibers:a Molecular Mechanics Study

A systematical research of f-CNF microstructure in terms of its structural stability based on stacked-cup and cone-helix model is conducted, employing molecular models and structural analyses followed by comparision with experimental observations. Four importantly structural features, e.g.,outer diameter, inner diameter, apex angle and number of layers, are evaluated separately and show profound influences on its structural stability. To this contribution, the maximum and minimum inner diameters could be also predicted by an empirical expression and geometric analysis of the CNF structure, respectively. Moreover, a strategy to calculate the number of carbon atoms in the nanocone is proposed, which is inconsistent with the number of simulated configuration. The origin of such structure-sensitive stability is elucidated by dividing the nanocone into six continuous parts to compare the corresponding energy. It is found that the structural stress concentrated around the top of the nanocone, especially for the f-CNF with small apex angle, would cause a threat to its structural stability. The negative effects could be weaken or eliminated by varying the thickness of the nanocone to compress the average carbon atom energy. As a result, the optimum thickness could be derived for nanocones with different apex angles while the same carbon atom number. A combination of the calculated results with experimental observations of f-CNF confirms the reliability of the proposed methology for the structural stability based on molecular mechanics study.