Influence of confinement in mesoporous silica on diffusion of a mixture of carbon dioxide and an imidazolium-based ionic liquid by high field diffusion NMR

Hazelbaker, Eric D.; Guillet‐Nicolas, Rémy; Thommes, Matthias; Kleitz, Freddy; Vasenkov, Sergey

doi:10.1016/j.micromeso.2014.12.005

Cited by 21 publications

(20 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This difference may arise from the ion size effect (DEMA + o C 6 C 1 Im + and OMs À o TFSI À ) that predicts a more pronounced 'restricted diffusion' when the molecular-to-pore radius ratio exceeds 0.1. 31 The magnitude of the mobility drop that we report is comparable with that recently reported by Hazelbaker et al, 32 who have observed a reduction by a factor of two for the self-diffusion of an imidazolium ionic liquid confined in mesoporous silica with pores larger than 5 nm. Apart from the extreme points investigated, i.e.…”

Section: View Article Onlinesupporting

confidence: 91%

Achieving enhanced ionic mobility in nanoporous silica by controlled surface interactions

Garaga¹,

Aguilera²,

Yaghini³

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

We report a strategy to enhance the ionic mobility in an emerging class of gels, based on robust nanoporous silica micro-particles, by chemical functionalization of the silica surface. Two very different ionic liquids are used to fill the nano-pores of silica at varying pore filling factors, namely one aprotic imidazolium based (1-methyl-3-hexylimidazolium bis(trifluoromethanesulfonyl)imide, CCImTFSI), and one protic ammonium based (diethylmethylammonium methanesulfonate, DEMAOMs) ionic liquid. Both these ionic liquids display higher ionic mobility when confined in functionalized silica as compared to untreated silica nano-pores, an improvement that is more pronounced at low pore filling factors (i.e. in the nano-sized pore domains) and observed in the whole temperature window investigated (i.e. from -10 to 140 °C). Solid-state NMR, diffusion NMR and dielectric spectroscopy concomitantly demonstrate this effect. The origin of this enhancement is explained in terms of weaker intermolecular interactions and a consequent flipped-ion effect at the silica interface strongly supported by 2D solid-state NMR experiments. The possibility to significantly enhance the ionic mobility by controlling the nature of surface interactions is extremely important in the field of materials science and highlights these structurally tunable gels as promising solid-like electrolytes for use in energy relevant devices. These include, but are not limited to, Li-ion batteries and proton exchange membrane (PEM) fuel cells.

show abstract

Section: View Article Onlinesupporting

confidence: 91%

Achieving enhanced ionic mobility in nanoporous silica by controlled surface interactions

Garaga¹,

Aguilera²,

Yaghini³

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…The activation energy of CO 2 permeation through the supported [bmim][BF 4 ] IL membrane was very close to the diffusion activation energy in the bulk IL (~6.0 kJ/mol) [16]. This observation is consistent with findings in the literature where CO 2 diffusivity in IL filled in nanoporous silica substrate was reported to be similar to or slightly greater than that in the bulk IL [17]. Because the apparent diffusion activation energies of N 2 and O 2 are much larger than that of the CO 2 , increasing temperature causes greater permeability enhancement for N 2 and O 2 than for CO 2 , leading to decline of CO 2 permselectivity.…”

Section: Single Gas Permeationsupporting

confidence: 89%

Colloidal Silicalite Coating for Improving Ionic Liquid Membrane Loading on Macroporous Ceramic Substrate for Gas Separation

Cao

Yang

Sun

et al. 2016

J. Memb. Separ. Tech.

View full text Add to dashboard Cite

A thin layer of colloidal silicalite was coated on a macroporous alumina substrate to improve the effectiveness in loading and supporting ionic liquid (IL) membrane on macroporous ceramic substrate. The [bmim][BF4] IL and CO2 gas separation were used as the model system in this research. The colloidal silicalite top layer enabled the formation of a pinhole-free IL membrane with significantly reduced load of IL as compared to the bare alumina substrate because the former had a smaller and more uniform inter-particle pore size than the latter. The supported IL membrane was extensively studied for CO2 separation in conditions relevant to coal combustion flue gases. The silicalite-supported IL membrane achieved a CO2/N2 permselectivity of ~24 with CO2 permeance of ~1.0 10-8 mol/m 2 •s•Pa in dry conditions at 26˚C and reached a CO2/N2 separation factor of ~18 with CO2 permeance of ~1.56 10-8 mol/m 2 •s•Pa for a feed mixture containing ~11% CO2 and ~9% water vapor at 50 o C. This supported IL membrane exhibited excellent stability under a 5bar transmembrane pressure at 103˚C and chemical resistance to H2O, SO2, and air (O2). Results of this study also indicated that, in order to fully realize the advantages of using the colloidal silicalite support for IL membranes, it is necessary to develop macroporous ceramic supports with optimized pore size distribution so that the IL film can be retained in the micron-thin silicalite layer without penetrating into the base substrate.

show abstract

“…An understanding of the properties of the ILs confined in a nanoscaleconstrained geometry is of both fundamental and practical interest. In particular, the spatial restriction and low dimensionality promote a strong interaction of the ILs with the walls of the confining matrix, resulting in physicochemical behavior of the confined ILs, in terms of phase transition behavior [29][30][31], wetting [32], layering near surface walls [33,34], as well as mobility [35][36][37], much different from the corresponding bulk properties.…”

Section: Introductionmentioning

confidence: 99%

Ionic liquids under nanoscale confinement

Borghi

Podestà

2020

Advances in Physics: X

View full text Add to dashboard Cite

The confinement of room-temperature ionic liquids (ILs) in nanoscale geometries, where at least one, but often all three dimensions are reduced down to lengths comparable to the anion-cation size, put the ILs into a quite different condition with respect to their bulk phase. An understanding of the properties of the ILs confined in a nanoscale-constrained geometry is of both fundamental and practical interest. In particular, the spatial restriction of ILs promotes a strong interaction of the ILs with the surface of the confining matrix, which strongly affects their properties, like the phase transition behavior, layering near surface walls, wetting, as well as ionic mobility. This short review is especially concerned with the interfacial confinement of ILs on solid substrates, in the form of very thin films, or inside porous nanomaterials.

show abstract

Influence of confinement in mesoporous silica on diffusion of a mixture of carbon dioxide and an imidazolium-based ionic liquid by high field diffusion NMR

Cited by 21 publications

References 23 publications

Achieving enhanced ionic mobility in nanoporous silica by controlled surface interactions

Achieving enhanced ionic mobility in nanoporous silica by controlled surface interactions

Colloidal Silicalite Coating for Improving Ionic Liquid Membrane Loading on Macroporous Ceramic Substrate for Gas Separation

Ionic liquids under nanoscale confinement

Contact Info

Product

Resources

About