Defect-free MoS₂ nanosheets: Advanced nanofillers for polymer nanocomposites

The preparation of defect-free MoS₂ nanosheets is a key challenge and essential for practical applications. Herein the dodecanethiol was firstly performed as the antioxidant and surface modifier to produce the defect-free MoS₂ by direct ultrasonication of bulk MoS₂ in N,N-dimethylformamide. Incorporating defect-free MoS₂ into polyethylene obviously improved the properties of PE/MoS₂ nanocomposites. For crystallization under quiescent condition, the half crystallization time (t_0.5) of nanocomposites containing 0.2 wt% MoS₂ was reduced by 87.0% compared to that of neat PE. A 54.3 °C increase in the temperature of maximum weight loss (T_max) was observed by inclusion of as low as 0.7 wt% defect-free MoS₂ nanosheets. In addition, the uniformly distributed MoS₂ can considerably improve the mechanical properties of composites. These observations suggest that the robust nature, dramatic barrier action of defect-free MoS₂ and the strong nanosheets/matrix interfacial adhesion would be the motivation to improve the performance of the polymeric nanocomposites.