A Simple Preparation of HDA-CuS Nanoparticles and Their Tribological Properties as a Water-Based Lubrication Additive

Abstract

In this paper, water-soluble CuS nanoparticles as water-based lubricant additives were synthesized by a simple surface modification method. Bis (2-hydroxyethyl) dithiocarbamic acid (HDA) was used as a modifier to ensure water solubility of nanoparticles, also acted as a reactant to offer sulfur source in this synthesis reaction of CuS. The tribological properties and thermal conductivity of as-prepared CuS nanoparticles modified by HDA (HDA-CuS) in distilled water were studied using UMT-2 micro friction tester and thermal conductivity meter. The results show that the as-prepared HDA-CuS nanoparticles can effectively improve the tribological behaviors and coefficient of thermal conductivity of distilled water. When the additive concentration is 0.8 wt%, the friction coefficient and wear rate are reduced by 78.3% and 93.7%, respectively, and the coefficient of thermal conductivity can be increased by 3%. The three-dimensional surface profiler, scanning electron microscope, and X-ray photoelectron spectroscopy were used to analyze the worn surface. It was found that a complex lubricating film was generated on the surface of the friction pairs during the friction process.