Abstract
Global concerns have arisen about the serious challenges of minimizing environmental effects while maintaining high performance requirements in the transportation, industrial, and agricultural sectors. The heavy reliance on compression-ignition engines, valued for their fuel economy, compactness, and high torque, presents a dilemma: how to sustain these advantages while transitioning from fossil fuels to more sustainable options? Blends of diesel, biodiesel, and bioethanol, known as "ternary blends," offer a viable path toward reducing emissions without requiring extensive modifications to existing engines. However, the chemical compatibility between (bio)fuels, particularly biodiesel, and conventional or bio-based lubricants can lead to significant changes in lubricant properties during prolonged engine operation. To address these issues, this thesis presents a comprehensive literature review of current technical challenges and explores recent advances in nanotechnology for improving lubricant stability and performance. The study emphasizes the promising role of SiO₂ nanoparticles, which, when surface-modified with KH570 silane coupling agent, enhance the physicochemical properties of conventional and biolubricants. After having formulated these nanolubricants through a two-step method, their correct dispersion stability was assessed using sedimentation photography, FTIR, and UV-Vis spectrophotometry, finding that optimized sonication times significantly improve dispersion stability. The addition of SiO₂ nanoparticles not only increased viscosity and density, but also contributed to a higher viscosity index without compromising acidity or the alkaline reserve, as confirmed by TAN and TBN analyses. Over a 77- day period, sedimentation was minimal, with bio-lubricants showing slightly higher sedimentation rates than conventional lubricants. Additionally, degradation tests under various temperatures and durations demonstrated that SiO₂ nanoparticles at concentrations of 0.75 wt% and 1.0 wt%, can effectively reduce oxidation respectively in conventional lubricants and in biolubricants. The Response Surface Methodology (RSM) applied to the experimental data facilitated model-based optimization, further validating the nanoparticles’ potential to enhance stability and longevity. By integrating SiO₂ nanoparticles, this study proposes a sustainable, high-performance solution that can prevent machinery degradation, reduce lubricant consumption, and extend maintenance intervals. The findings underscore the significant role of nanolubricants in advancing sustainable practices in agricultural and industrial applications, promoting environmentally friendly alternatives to traditional lubricants without sacrificing engine efficiency. This research contributes to a more sustainable future for key industries and supports the practical application of nanotechnology in enhancing the performance and environmental compatibility of lubricants and biolubricants.