Mucus-inspired biomass-derived carbon dots-based solvent-free nanofluid with polyelectrolytes networks toward excellent green lubrication

Mechanical friction and wear account for 23 % of global energy, highlighting a need for eco-friendly lubricants. Drawing inspiration from marine organisms' adsorption proteins, we have developed carbon dots-based solvent-free nanofluid. Incorporating hydrophilic polyelectrolytes, the nanofluid forms three-dimensional adsorption-lubrication networks, leveraging carbon dots' strong chelating affinity, synergistically enhancing lubrication. Using the UMT-3 TriboLab and a 3D optical profilometer, we assessed the tribological performance of nanofluid and remarkably reduced the friction coefficient by 47.3 % and wear rate by 90.8 % compared to PEG 200 (Polyethylene Glycol with an average molecular weight of 200). Additionally, the infrared camera detected that nanofluid as water additives, significantly reduce wear and heat generation, decreasing temperature rise by 4.7 times. This biomimetic approach paves the way for green, oil-free, and high-performance water-based lubrication technologies.