An imidazolium ionic liquid as effective structure-directing agent for the fabrication of silica thin films with vertically aligned nanochannels
Journal article, 2020

In parallel to the increasing variety of ionic liquids that show different kinds of nanometer-scale structuration in their pure and solved forms, there is a raising interest in exploring the possibility of using ionic liquids as soft-templates for the synthesis of mesoporous materials. We report the case of 1-hexadecyl-3-methylimidazolium chloride (C16MIMCl), a surface active ionic liquid (SAIL), here used as an excellent soft-template for the formation of vertically aligned, uniform mesochannels, with a well defined pore width of 2.5 nm in silica thin films deposited with the electrochemically assisted self-assembly (EASA) method. The obtained mesochannels run through the entire thickness of the films and after removal of the ionic liquid the emptied mesochannels ensure a thorough mass transport to the substrate, here monitored by the redox-active electrochemical probe Ru(II)/Ru(III) during cyclic voltammetry (CV). Moreover, the mechanism of pore formation is explained; unlike the mechanisms reported for short chain imidazolium ionic liquid silica templates, in the case of C16MIMCl the dominating so-called cooperative interaction is the electrostatic attraction between the C16MIM+ and the network-forming negatively charged silicate oligomers. Therefore, this study provides a better understanding of the templating behavior of long chain imidazolium ionic liquids and motivates further research on the synthesis of ionic liquid-based functional hybrid materials.

Surface active ionic liquids (SAILs)

Oriented nanochannels

Porous silica thin films


Szilvia Vavra

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Neus Vilà

University of Lorraine

Antiope Lotsari

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Alain Walcarius

University of Lorraine

Anna Martinelli

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Microporous and Mesoporous Materials

1387-1811 (ISSN)

Vol. In Press 110407

Combining acid-base chemistry with self-assembly for enhanced proton conduction in protic ionic liquids

Swedish Research Council (VR) (2018-05207), 2019-01-01 -- 2022-12-31.

Subject Categories

Inorganic Chemistry

Physical Chemistry

Materials Chemistry



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