Thermal characteristics of heat exchange fluids are an important field of research. Traditional heat exchange fluids like oils, ethylene glycol, and water have limited cooling potential due to their poor thermal conductivity.
There is increasing emphasis on the design of highly efficient base fluid thermal systems to improve heat transmission. Base fluids, like oils, are often used for lubrication in various industries.
Nanolubricants can be described as engineered fluid modified by incorporating different nanoscale materials, including metals, carbides, oxides, and nitrides. Nanomaterials like nanoparticles (NPs), nanotubes, or nanorods can be incorporated into base fluids.
Advantages of Nanolubricants
Achieving sustainable performance and energy conservation in mechanical systems necessitates using environmentally friendly and high-performance lubricants. Nanoparticles have recently become increasingly integral as lubricant additives due to their ability to reduce emissions and improve fuel efficiency.
The small size of NPs, often 100 nm or smaller, allows them to access the contact areas. In contrast to natural additives, NPs are thermally stable at high temperatures, making them suitable as additives in lubricants.
The team investigated the stability of graphene-based polyester oil nanolubricant via two particular two-step dispersion techniques: overhead stirrer with sonication and magnetic stirrer with sonication.
The sedimentation image was used to test the stability of nanolubricant dispersion over the course of a 14-day period.
Once the results of the study were confirmed, the team analyzed the specimens via the zeta potential analyzer to verify the stability of the nanolubricant.
The zeta potential is used to predict the stability of nanofluids. Nanofluids are stable at zeta potentials greater than ±30 mV, whereas any values less than ±30 mV are indicative of severe aggregation of nanoparticles.
The team found that different distribution strategies produced varying suspension stabilities.
Of the two-step approaches analyzed in this study, the overhead stirrer with sonication approach proved to be the most effective in developing a stable suspension.
This research concluded that the introduction of surfactants to a nanolubricant impacts its dispersion stability. Hexadecyltrimethylammonium bromide (CTAB) was found to improve nanolubricant stability as a surfactant in all dispersion techniques.
Date: Jul 25 2022