Effects of carbon nano onions on the tribological performance of food‐grade calcium sulfonate complex grease

Abstract

To improve the lubricity of the as‐prepared food‐grade calcium‐based grease, the effects of nano‐additive carbon nano onions (CNOs) on the tribological properties are systematically investigated using a ball‐disc wear tester. The properties of CNOs‐containing food‐grade calcium sulfonate complex greases (CSCG‐FG) were characterised by thermogravimetric analyser, rheometer and electrochemical workstation, Listeria monocytogenes, X‐ray photoelectron spectrometer and Raman spectrometer. The results revealed that pure and CNOs‐containing CSCG‐FG were proved to be safe. The average coefficient of friction (aCoF) and wear volume of the disc at CSCG‐FG of 0.10 wt% CNOs were the minimal values, which were 31.4 and 70.0% less than that of pure CSCG‐FG at 25°C and greatly lower than that of similar commercial food‐grade grease. At high temperature, CNOs‐containing CSCG‐FG had lower aCoFs and torques. CSCG‐FG of 0.10 wt% CNOs would be most possibly used in engineering applications and the results will provide valuable insight into developing food‐grade lubricants.

Fabrication of Garlic Oil-Functionalized Onion-Like Carbon Nanoparticles as Effective Nanoadditives for Improved Lubricating Performance

“…Nano-onion-like fullerene, a member of the zero-dimensional fullerene family, is commonly referred to as onion-like carbon (OLC), which exhibits near-spherical structures composed of multiple layers of closed fullerene carbon shells . Due to its unique structural characteristics, OLC possesses a high specific surface area and mechanical strength, both of which are conducive to its lubricating effect. − He et al prepared high-purity and high-reproducibility OLC via a one-step gas-phase explosion method, which improves the lubricating ability of 150SN mineral oil as a lubricant additive . Wang et al incorporated OLC as an additive into calcium sulfonate complex grease and found that the lubricating performance of the grease improved significantly with 0.10 wt % addition, reducing the average COF and wear volume by 31.4 and 70.0%, respectively .…”

“…14 Wang et al incorporated OLC as an additive into calcium sulfonate complex grease and found that the lubricating performance of the grease improved significantly with 0.10 wt % addition, reducing the average COF and wear volume by 31.4 and 70.0%, respectively. 15 The OLC usually ranges in size from 2 to 220 nm, and various preparation methods are employed, including arc discharge, 18 hydrothermal synthesis, 19 vacuum heat treatment, 20 combustion. 21 Especially, the preparation of OLC by collecting candle ash from burned candles has the salient features of simplicity and cost effectiveness, making it widely used.…”

“…Due to its unique structural characteristics, OLC possesses a high specific surface area and mechanical strength, both of which are conducive to its lubricating effect. − He et al prepared high-purity and high-reproducibility OLC via a one-step gas-phase explosion method, which improves the lubricating ability of 150SN mineral oil as a lubricant additive . Wang et al incorporated OLC as an additive into calcium sulfonate complex grease and found that the lubricating performance of the grease improved significantly with 0.10 wt % addition, reducing the average COF and wear volume by 31.4 and 70.0%, respectively . The OLC usually ranges in size from 2 to 220 nm, and various preparation methods are employed, including arc discharge, hydrothermal synthesis, vacuum heat treatment, and organic combustion .…”