Multifunctional additives for lubricating oil

These functions are essential for maintaining engine durability, preserving lubricant performance and improving energy efficiency, thereby supporting long-term decarbonisation targets. However, conventional additive technologies rely heavily on metals, sulfur and phosphorus, which are increasingly restricted due to environmental concerns and incompatibility with modern after-treatment systems.

This thesis addresses the need for more sustainable alternatives by exploring lubricant additive systems based on second-row elements, with particular emphasis on boron- and nitrogen-containing chemistries.<br><br>Two distinct additive strategies were investigated. In the first, dispersed covalent organic framework (COF) materials were evaluated in low-viscosity base oils. While certain COF structures exhibited limited effectiveness due to dispersion instability, alternative frameworks demonstrated clear potential to reduce friction and wear when appropriately stabilised, highlighting the importance of structural features and formulation compatibility.