Jump to main content
Jump to site search

Issue 38, 2012
Previous Article Next Article

An investigation of the sol–gel process in ionic liquid–silica gels by time resolved Raman and 1H NMR spectroscopy

Author affiliations

Abstract

We report, by employing time resolved Raman and nuclear magnetic resonance (NMR) spectroscopy, on the gelation process in ionogels. These are prepared from a non-aqueous sol–gel reaction in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C1C6ImTFSI). Raman and NMR spectroscopies are complementarily used to decipher the chemical reactions that occur during synthesis and to clarify the state of the ionic liquid up to, and well beyond, gelation. We find that the ionic liquid concentration affects both the reaction rate and the gelation time (tgel). In addition, NMR and Raman data reveal inherently different roles of the cation and the anion in the gelation process. While the oscillating behavior of the TFSI Raman signature at ∼740 cm−1 is mainly an effect of solvation and chemical composition, the evolution of the relative chemical shifts (Δδ) of different hydrogen atoms on the imidazolium correlates with gelation, as does the width of the chemical shift of –OH containing groups (δOH). We also observe that in the confined state the TFSI anion preferably adopts the cisoid conformation and experiences a stronger ion–ion interaction.

Graphical abstract: An investigation of the sol–gel process in ionic liquid–silica gels by time resolved Raman and 1H NMR spectroscopy

Back to tab navigation

Supplementary files

Publication details

The article was received on 07 Jun 2012, accepted on 20 Jul 2012 and first published on 31 Jul 2012


Article type: Paper
DOI: 10.1039/C2CP41914A
Phys. Chem. Chem. Phys., 2012,14, 13216-13223

  •   Request permissions

    An investigation of the sol–gel process in ionic liquid–silica gels by time resolved Raman and 1H NMR spectroscopy

    A. Martinelli and L. Nordstierna, Phys. Chem. Chem. Phys., 2012, 14, 13216
    DOI: 10.1039/C2CP41914A

Search articles by author

Spotlight

Advertisements