## 1 Introduction
At a 0.1% nanoparticle concentration, the study saw a 50% reduction in wear rate and an 18.46% decrease in the friction coefficient. Furthermore, the lubricant's flash point increased by 3.8% as a result of the nanoparticle addition [27]. However, enhancing the stability of nanolubricants requires a comprehensive strategy that extends beyond simple physical treatments. Integrating chemical techniques with physical methods, such as adding surfactants and modifying the surface properties of nanoparticles, results in a nanolubricant formulation that is more resistant to corrosion. This improved resistance pertains to both protecting the material surfaces in contact with the nanolubricant and ensuring the chemical stability of the nanoparticles themselves. The widespread consumption of petroleum-based lubricants has given rise to growing concerns, sparking an increasing interest in the use of readily biodegradable alternatives, particularly biolubricants [28]. In addition to this fact, there is also the inevitable leakage of lubricants on the ground that occurs in fast connectors for hoses used to connect agricultural tractors and implements, as well as used in construction machinery to connect different attachments. According to an informal survey conducted among contractors in Northwest Italy, it was found that hydraulic couplers without oil collectors can result in oil leaks of up to 2 L per year per tractor [29; 30]. Biolubricants, including plant oils, animal fats, or their chemically modified derivatives, are generally acknowledged for their environmentally friendly characteristics due to their exceptional biodegradability and renewable feedstock [31]; in addition, they constitute the ideal evolution of currently used synthetic and mineral lubricants. So, the idea behind the experimentation illustrated in this article is to propose and test the properties of a mix of nanoparticles and biolubricant, namely a \"nano-bio-lubricant\". This novel lubricant showed the enhanced properties of all nanolubricants, which were well described in the literature, together with better biodegradability/environmental compatibility of biolubricants, in a formulation that bridged actual and future mechanical systems. Therefore, this article assessed the importance of silicon dioxide (SiO\({}_{2}\)) nanoparticles coated with a KH570-Silane coupling agent, concentrating on their use in conventional and eco-friendly biolubricants. Specifically, SiO\({}_{2}\) was selected for its advantageous additive effects, such as its ability to efficiently minimize wear and friction of components in relative motion, in addition to its biocompatibility, which is crucial for applications involving environmental and health concerns. Indeed, SiNPs, specifically SiO\({}_{2}\) nanoparticles, have been extensively studied and are widely used in biomedical applications, where safety is of utmost concern. For example, the study by [PERSON] et al. [32] demonstrates that SiO\({}_{2}\) nanoparticles exhibit high biocompatibility across various cell lines, with no significant cytotoxic effects observed under specific conditions. Instead, \(\gamma\)-methacryloyloxypropyltrimethoxysilane, or KH570, was selected for surface modification applications because of its known efficacy. It interacts with the surface hydroxyl groups of silicon dioxide nanoparticles through the presence of a hydrolyzable ethoxy group. Furthermore, KH570's amino group offers functional groups for additional reactions or attachments to other substances or molecules. By modifying the surface of SiO\({}_{2}\) nanoparticles, the KH570-Silane coupling agent improves their compatibility with diverse systems and increases their dispersibility in a range of matrices or solvents. By strengthening their surface modification, SiO\({}_{2}\) nanoparticles become more stable, which decreases aggregation and boosts their overall performance across a range of applications.