Improved tribological properties of MXene nanosheet filler-modified PPO composites

Abstract

MXenes, a class of two-dimensional (2D) nanomaterials, exhibit exceptional properties such as outstanding mechanical and thermal stability, along with diverse surface characteristics, making them highly promising in the tribology. However, their tendency to aggregate within the polymeric matrix adversely affects the tribological performance of the polymer. In this study, glass fiber (GF) surfaces were modified with polydopamine (PDA), allowing smaller MXene nanosheets to adhere to the GF surface, whereas the larger MXene nanosheets were dispersed throughout the matrix. This approach effectively enhanced the dispersion of MXene nanosheets in the polymeric matrix, facilitating the preparation of polyphenylene oxide (PPO)/MXene composite materials. Compared with the pure PPO sample, the results showed that the average friction coefficient and wear rate of the PPO/MXene composites were reduced by 46.25% and 98.34%, respectively, due to the distinct roles of different MXene nanosheet sizes in the polymeric matrix. Furthermore, a uniform lubricating film was formed during the friction of the polymer composite, enhancing its tribological performance. This study proposes a novel design strategy to enhance MXene nanosheet dispersion and optimize their lubricating properties.