Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 150469

150469 - Choline Amino Acid Ionic Liquid: Tribological Performance as a Lubricant Additive to Polar and Non-Polar Base Oils 

Ionic liquids (ILs) are known to reliably accomplish their role as lubricant additives while persisting in being an environmentally friendly alternative to their conventional counterparts. Blending ILs at a concentration of only 1 wt% with base oils can significantly enhance the lubricity of the base oil. On the other hand, the base oil’s polarities can mediate how efficiently it chemically interacts with ILs, which substantially varies its tribological performance. Choline amino acid ionic liquids (ChAAILs), a subclass of protic ionic liquids (PILs) composed of only renewable, biodegradable, and biocompatible products, are nominated as additives to investigate that variability. Commercially available esterex polyol ester (EST) serves as a polar base oil, while SpectraSyn polyalphaolefin (PAO) serves as a non-polar base oil. Upon performing tribological tests and investigating the lubricity of the lubricants, the results showed that the polarity of its base oil has noticeably influenced the tribological performance of the ChAAILs additive.

Aspartic acid IL ([CHO][ASP]) was synthesized and 1 wt% of this synthesized [CHO][ASP] was added to both base oils to form the additives. The mixture was stirred magnetically and then subjected to ultrasonic sound for an hour for homogeneous properties. The solubility of the synthesized PIL in both base oils was investigated and for thermal properties, thermogravimetric analysis and differential scanning calorimetry were conducted on PAO, EST, PAO+[CHO][ASP], and EST+[CHO][ASP] . A temperature ramp viscosity tests were also performed on the lubricants to study their variation in viscosity with temperature. Furthermore, three friction tests were run on both AISI 52100 steel or 6061 aluminum polished disks contacted against AISI 52100 steel balls using about 2 ml of each lubricant in a ball-on-flat configuration. All tests were performed with a normal load of 3N, a frequency of 5Hz, a stroke length of 3 mm, and a sliding distance of 108 m. Using an optical microscope to measure the wear track width, the worn disk surfaces were characterized and further studied using a scanning electron microscope, energy-dispersive X-ray spectroscopy, and a 3D profilometer.

The preliminary results show variation in friction and wear between different material contacts and the base oils used. In the steel-steel contact, the additive EST+[CHO][ASP] reduced wear and friction more than the PAO+[CHO][ASP] additive by about 44% and 22%, respectively. On the flip side, in the steel-aluminum contact, there were no significant differences in friction, while the wear of EST+[CHO][ASP] is more than double the wear of PAO+[CHO][ASP]. Nonetheless, the addition of 1 wt% to either base oil has demonstrated a reduction in friction and wear. In steel-aluminum contacts, the wear was substantially higher with EST+[CHO][ASP], highlighting the importance of base oil polarity and material compatibility in enhancing lubricity. Future work will focus on optimizing the concentration of ChAAILs for different base oils and exploring their performance in real-world applications. Additionally, the long-term stability and environmental impact of these ionic liquids will be further investigated to ensure their practical viability as green lubricants.

Presenting Author: Davis Kiboi Rochester Institute of Technology

Presenting Author Biography: Davis Kiboi is currently a PhD student at the Rochester Institute of Technology. His research focuses on the wear and friction of materials, with a particular interest in ionic liquids as lubricants and lubricant additives, as well as bio-lubricants. With a background in mechanical and vehicle engineering, Kiboi is dedicated to enhancing the performance and sustainability of mechanical and automotive systems through innovative lubrication solutions. His work involves synthesizing and testing novel ionic liquids and exploring their potential to reduce friction and wear in various industrial applications. In addition to his academic pursuits, Davis is passionate about promoting eco-friendly engineering practices and contributing to the advancement of green technology.

Authors:

Davis Kiboi Rochester Institute of Technology
Esmond Lau Rochester Institute of Technology
Moni Chavez Rochester Institute of Technology
Filippo Mangolini The University of Texas at Austin
Patricia Iglesias Rochester Institute of Technology