Synthesis and Characterization of a Novel Two-Dimensional Copper p-Aminophenol Metal–Organic Framework and Investigation of Its Tribological Properties

Here, a novel copper p-aminophenol metal–organic framework (Cu(PAP)(2)) is first reported. Powder X-ray diffraction (PXRD), infrared spectra (FTIR), Raman spectra, transmission electron microscopy (TEM) and X-ray photoemission spectroscopy (XPS), in combination with a structure simulation, indicated that Cu(PAP)(2) is a two-dimensional (2D) material with a staggered structure analogous to that of graphite. Based on its 2D graphite-like layer structure, Cu(PAP)(2) was expected to exhibit preferable tribological behaviors as an additive in liquid lubricants, and the tribological properties of Cu(PAP)(2) as a lubricating additive in hydrogenated polydecene (PAO6) or deionized water were investigated. Compared to PAO6 or deionized water, the results indicated that deionized water-based Cu(PAP)(2) showed much better friction reduction and anti-wear behavior than PAO6-based Cu(PAP)(2) did, which was due to Cu(PAP)(2) penetrating the interface between friction pairs in deionized water, but not in PAO6, thus producing lower friction and wear resistance values.