Novel fatty acid anion-based ionic liquids: Contact angle, surface tension, polarity fraction and spreading parameter

摘要

This work deals with the determination of several wetting properties (contact angle, surface tension, polarity fraction and spreading parameter) of six novel fatty acid anion-based ionic liquids (FAILs): methyltrioctylammonium hexanoate [N-8881][C-6:0], methyltrioctylammonium octanoate [N-8881][C-8:01], methyltrioctylammonium laurate [N-8881][C-12:0], methyltrioctylammonium palmitate [N-8881][C-16:0], methyltrioctylammonium stearate [N-8881] [C-18:0] and methyltrioctylammonium oleate [N-8881][C-18:1]. Surface tension was determined at temperatures from 293 to 333 K, exhibiting a linear decrease within the temperature range. Contact angle measurements were performed on five different surfaces (steel, aluminum, tungsten carbide, cast iron and bronze) using 3 test liquids (water, diiodomethane and ethylenglycol) and each of the synthesized FAILS. Polarity fraction (PF) and the spreading parameter (SP) were calculated in order to gain a deeper understanding of wetting characteristics of these FAILS. Despite the similarity of the obtained results with all FAILS and surfaces, [N-8881][C-6:0] and [N-8881] [C-8:0] with both cast iron and bronze surfaces were the best surface-FAIL combinations regarding wettability. (C) 2019 Elsevier B.V. All rights reserved.