Wetting properties of five low-melting mixture solvents based on glycerol

This work studies the wetting properties of five low-melting mixture solvents (LoMMSs) based on glycerol synthesized using choline acetate, betaine, proline, lysine, and arginine as hydrogen bond acceptors. The study aims to evaluate their surface tension, contact angle, and contact angle hysteresis, key parameters for understanding interfacial behavior in lubrication applications. Surface tension was measured over a range of temperatures, while dynamic contact angle and hysteresis were determined at room temperature through advancing and receding measurements on a platinum‑iridium surface using the Wilhelmy plate method. Prior to these experimental assessments, the COSMO-RS sigma profiles of the LoMMSs and their precursors were generated to estimate molecular polarity. The results revealed notable differences in wetting behavior among the LoMMSs. The choline acetate-based LoMMS exhibited the lowest contact angle and hysteresis, indicating superior surface spreading. Proline and betaine-based LoMMSs showed intermediate wettability, while the lysine and arginine-based LoMMSs displayed the highest contact angles and hysteresis, reflecting lower substrate affinity and higher viscosity. Overall, the findings demonstrate that wetting properties are strongly influenced by both polarity and viscosity, as well as by the molecular structure. The addition of both glycerol and water improves wettability. The study underscores the importance of contact angle and hysteresis analysis in evaluating the tribological potential of LoMMSs, particularly in applications requiring efficient surface coverage and stable lubricating films to minimize friction and wear. • Choline acetate LoMMS showed the lowest contact angle and contact angle hysteresis. • COSMO-RS sigma profiles were generated to estimate the molecular polarity of LoMMSs. • Sigma profiles linked molecular polarity to wetting behavior. • Findings can help LoMMSs design for improved lubrication performance.