Liquid-exfoliated MoS₂ by chitosan and enhanced mechanical and thermal properties of chitosan/MoS₂ composites

A simple and large-scale method to prepare molybdenum disulfide (MoS₂) nano-flakes by the sonication of its bulk material in an acid aqueous solution of chitosan (CS) was developed. Transmission electron microscopy (TEM) images suggested that the MoS₂ was exfoliated into few-layer or mono-layer thin sheets. Specifically, MoS₂ dispersion was directly employed to fabricate the chitosan/MoS₂ composites. The results obtained from the TEM images and X-ray diffraction (XRD) patterns showed that the MoS₂ flakes were homogeneously dispersed in the composites at an appropriate content. The tensile test, dynamic mechanical analysis and thermogravimetric analysis results indicated that the mechanical and thermal properties of CS films were remarkably improved by the incorporation of MoS₂, which was attributed to the well dispersion state and the reinforcing effect of the MoS₂ nanofillers with unique two-dimensional (2D) structure.