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Paporakis S, Liu KTC, Brown SJ, Harper JB, Martin AV, Greaves TL. Thermal Stability of Protic Ionic Liquids. J Phys Chem B 2024; 128:4208-4219. [PMID: 38650054 DOI: 10.1021/acs.jpcb.3c08011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
While protic ionic liquids (ILs) have found great success as solvents for a broad range of applications, little is known about their degradation when exposed to temperatures above ambient for extended periods of time. Here, we report the thermal stability of six protic ILs, namely, ethylammonium nitrate, ethylammonium formate, ethylammonium acetate, ethanolammonium nitrate, ethanolammonium formate, and ethanolammonium acetate. The effect of heating each ionic liquid to 60 °C for 1 h or 1 week (sealed or open to the atmosphere) was evaluated by considering the changes to water content, pH, mass, thermal phase transitions, and molecular structure after each treatment. Heating each of the six ILs when sealed led to measurable shifts in their water content and 10 wt % pH, but there was no significant change in their mass, thermal phase transitions according to differential scanning calorimetry (DSC), or molecular structure using proton nuclear magnetic resonance (1H NMR) spectra, indicating that the samples were largely unchanged. The samples that were heated open to the atmosphere also displayed no significant changes after 1 h but displayed significant changes after 1 week.
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Affiliation(s)
- Stefan Paporakis
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne ,VIC 3000, Australia
| | - Kenny T-C Liu
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne ,VIC 3000, Australia
| | - Stuart J Brown
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne ,VIC 3000, Australia
| | - Jason B Harper
- School of Chemistry, University of New South Wales, UNSW, Sydney, NSW 2052, Australia
| | - Andrew V Martin
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne ,VIC 3000, Australia
| | - Tamar L Greaves
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne ,VIC 3000, Australia
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Effect of spacer alkyl chain length on retention among three imidazolium stationary phases under various modes in high performance liquid chromatography. J Chromatogr A 2022; 1685:463646. [DOI: 10.1016/j.chroma.2022.463646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/25/2022] [Accepted: 11/10/2022] [Indexed: 11/14/2022]
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Zhou S, Hu Z, Zhang Y, Wang D, Gong Z, Fan M. Differentiation and identification structural similar chemicals using SERS Coupled with different chemometric methods:the example of Fluoroquinolones. Microchem J 2022. [DOI: 10.1016/j.microc.2022.108023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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