A relatively recent lubrication technique is hybrid nanolubrication, involving the combination of two or more forms of nanoparticles, either in a mixture or in a composite form, in a base fluid. Hybrid nanolubrication, especially in terms of thermal properties or rheological properties, has been documented to contribute to great improvement compared to that of individual nanolubrication. Likewise, bio-based oils have excellent properties and harnessing these qualities by combining bio-based oils together with hybrid nanoparticles could possibly further improve the thermal conductivity characteristics of hybrid nanolubricants. Therefore, due to the approach novelty, possible elevated performance coupled with increased sustainability, synthesizing hybrid nanolubricants using bio-based oil is deemed necessary. However, like other new advancements, information is scarce, and further and deeper explorations are required so as to better understand the heat transfer characteristics of these bio-based hybrid nanolubricants and to validate the above-mentioned proposition. Hence, in this work, the contrariety of thermal conductivity of bio-based hybrid nanolubricant using coconut oil with coco amido propyl betaine (CAPB) has been investigated. Through this investigation, the thermal conductivity of this bio-based hybrid nanolubricants has been found to increase with the increase of hybrid nanoparticles concentration and decrease with the increase in temperature. The addition of SDBS and CAPB into this bio-based hybrid nanolubricant also stabilizes it making this sustainable lubricant potentially applicable in industrial settings. Coconut oil based hybrid nanolubricant shows better thermal conductivity compared to Solcut oil based. The thermal performance of coconut oil works best at 30 °C while Solcut oil at 40 °C. This due to better stability of the suspensions of Solcut oil compared to coconut oil.
