Ionic Liquids with Benzenesulfonate Anions: Non-Fluorinated, Thermally Stable Anion Options

ACS Appl Eng Mater. 2023 Jan 27;1(1):690-695. doi: 10.1021/acsaenm.2c00229. Epub 2023 Jan 13.

Abstract

Thermally resistant materials have been sought after for use as lubricants, heat transfer fluids, high temperature structural materials, and other applications where thermal stability is required or desired. Herein, we present a new class of thermally robust ionic liquids containing inexpensive benezenesulfonate anions with profound long-term, high-temperature aerobic stability - i.e., no mass loss in 96 hours at 300 °C in air. A coherent correlation between melting and glass transition temperatures and the location and type of the anions was observed. Our work indicates that these systems can be designed to form thermally stable, low-melting organic salts, providing valuable design insights for engineering of their structure-property-function relationships.

Keywords: Benzenesulfonates; Functional organic materials; Ionic liquids; Structure–property–function relationship; Thermally resistant materials.