## 4 Conclusions  
1. In the static composite system, when the CNT is surrounded by multiple random polymer chains, the CNT has a tendency to induce the orientation of molecular chains. However, under the restriction of the surrounding molecular chain segments, the molecular chains are unable to complete large-scale migration movements, and the conformation adjustment of the molecular chains is limited. Thus, the orientation and radius of gyration of the molecular chains change little.
2. In the sheared pure PE system after the cessation of shear, the Brownian motion of the oriented molecular chains is active. The molecular chains overcome the viscous flow activation energy and relax dramatically. A significant conformation change rapidly occurs, from an oriented to a winded state, and so the conformation size of the molecular chains is markedly reduced.
3. Under the adsorption and inhibition of the CNT in the sheared composite system, the conformation of the oriented chains stabilizes. Moreover, under the induction of the CNT, the molecular chains are further extended, orientation degree is further improved, and the arrangement is more regular and orderly. Compared with the isolated effects of shear flow and the CNT, the combination of the two has a more obvious effect on the conformation size and orientation degree of the molecular chains. Furthermore, the orderly arrangement of molecular chains is closer to a lattice structure,  
Figure 8: RDF of carbon atoms in PE chains along the CNT radial direction.  
Figure 7: The radial distribution function (RDF) of hydrogen atoms in PE chains along the carbon nanotube (CNT) radial direction.  
and the kinetic barrier to be crossed is relatively small, promoting the interface crystallization of the composite system.
4. The RDF peak values of C and H atoms in the sheared composite system are higher than those in the static composite system, the van der Waals force increases, and the interface binding energy increases correspondingly, which indicates that the interface interaction between PE molecular chains and CNTs can be enhanced to some extent through interface crystallization. Moreover, by changing the process conditions of injection molding, the molecular chains can have different orientation degrees, so as to regulate the degree and morphology of crystallization at the interface.  
Conceptualization, data curation, and formal analysis, M.Z.; funding acquisition, Y.X.; investigation and methodology, M.Z.; project administration and supervision, Y.X.; visualization, M.Z.; writing--original draft, and review and editing, M.Z. and Y.X. All authors have read and agreed to the published version of the manuscript.  
This study was supported by the National Natural Science Funds of China (No. 51365038) and College Science and Technology Project of the Government of Jiangxi Province (No. KJLD12058).  
The financial support from the National Natural Science Funds of China (No. 51365038) and College Science and Technology Project of the Government of Jiangxi Province (No. KJLD12058) is gratefully acknowledged. We express our gratitude to the Shenzhen Cloud computing center for computing support and help. We also appreciate the efforts of the journal editor for editing this paper.  
The authors declare no conflict of interest.