Fabrication of Zwitterionic Polymer-Functionalized Onion-like Carbon Nanoparticles as Aqueous Lubricant Additives

Abstract

Onion-like carbon (OLC) is a kind of carbon material with a graphene-like structure and large interlayer spacing, favorable to a good lubricating performance. Herein, a facile method is presented for the preparation of functionalized OLC nanoparticles from candle soot with surface modification. The OLC nanoparticles are collected from combustion soot with candle burning via a simple heat treatment, and then the zwitterionic polymer (polyethylenimine-quaternized derivative, PEIS) can self-assemble onto the OLC surface with epigallocatechin gallate via Michael addition and Schiff-base reaction, thus obtaining PEIS-functionalized OLC nanoparticles (PEIS@OLC). The grafting zwitterionic polymer PEIS endows the OLC nanoparticles with good hydrophilic performance, so the as-obtained PEIS@OLC exhibits outstanding dispersion and lubricating property as a water-based lubricant additive. Compared to pure water, the average coefficient of friction decreases to 0.110 from 0.512, and the corresponding wear volume is reduced by 61.02% with 1.5 wt % addition. The improved lubricating property is mainly due to the synergetic effect of the protective film induced by the tribochemical reaction and the hydration film of zwitterionic polymer PEIS. Besides, the OLC nanoparticles could also display the nanoscale rolling and repairing effects at the friction contact interface, resulting in reduction of friction and wear.

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

“…The collected candle ash was heat-treated to 450 °C to prepare the OLC nanoparticles (Scheme ). Under alkaline conditions, PEI can form a cross-linked PEI polymer via the Schiff-base reaction and Michael addition reaction with EGCG, which then in situ assembles on the OLC surface through van der Waals and π–π interactions . Subsequently, garlic oil can be grafted onto the cross-linked polymer layer via the aza-Michael reaction with PEI to prepare garlic oil-functionalized onion-like carbon (GO@OLC) .…”

Mechanochemical Synthesis of Thiadiazole Functionalized COF as Oil-Based Lubricant Additive for Reducing Friction and Wear

“…In practical application, single base lubricants are often inaccessible to attain desired lubrication properties, especially under extreme conditions of heavy load, high frequency, and high temperature, lubrication failure is often generated. Therefore, indispensable lubricant additives have been diffusely designed and applied to improve the lubrication performance of base lubricants, such as surfactants, antiwear agents, and corrosion inhibitors. − …”

Preparation of Hydrophilic Hyper-Cross-Linked Polystyrene Nanospheres with Antibacterial for Improved Water Lubrication Performance

“…With the continuous advancement of nanotechnology and deep understanding of the distinctive properties of functional nanomaterials, nanoparticles as additives exhibit exceptional physical and chemical characteristics, thereby presenting extensive prospects for application in the lubrication field . Metals, metal oxides, metal sulfides, carbon-based materials, polymers, and composite materials are used as water-based lubricant additives. Polymers exhibit advantageous characteristics such as facile processability, low thermal conductivity, electrical conductivity, and exceptional resistance to corrosion.…”