Diamond nanothread as a new reinforcement for nanocomposites

TL;DR

This study investigates diamond nanothreads as a new reinforcement in nanocomposites, demonstrating their strong interfacial load transfer capabilities comparable to carbon nanotubes, and how surface modifications can further enhance this property.

Contribution

It introduces diamond nanothreads as a novel reinforcement material and analyzes their interfacial shear strength in polyethylene nanocomposites through in silico studies.

Findings

DNT/PE interface has high shear strength comparable to CNT/PE.

Irregular surface of DNT enhances non-covalent load transfer.

Increasing PE density or functional groups improves interfacial strength.

Abstract

This work explores the application of a new one-dimensional carbon nanomaterial, the diamond nanothread (DNT), as a reinforcement for nanocomposites. Owing to the existence of Stone-Wales transformation defects, the DNT intrinsically possesses irregular surfaces, which is expected to enhance the non-covalent interfacial load transfer. Through a series of in silico pull-out studies of the DNT in polyethylene (PE) matrix, we found that the load transfer between DNT and PE matrix is dominated by the non-covalent interactions, in particular the van der Waals interactions. Although the hydrogenated surface of the DNT reduces the strength of the van der Waals interactions at the interface, the irregular surface of the DNT can compensate for the weak bonds. These factors lead to an interfacial shear strength of the DNT/PE interface comparable with that of the carbon nanotube (CNT)/PE interface. Our results show that the DNT/PE interfacial shear strength remains high even as the number of Stone-Wales transformation defects decreases. It can be enhanced further by increasing the PE density or introduction of functional groups to the DNT, both of which greatly increase the non-covalent interactions.