Exploring the bulk-phase structure of ionic liquid mixtures using small-angle neutron scattering

TY - JOUR

T1 - Exploring the bulk-phase structure of ionic liquid mixtures using small-angle neutron scattering

AU - Cabry, Christopher Patrick

AU - D'Andrea, Lucia

AU - Shimizu, Karina

AU - Grillo, Isabelle

AU - Li, Peixun

AU - Rogers, Sarah

AU - Bruce, Duncan Watson

AU - Canongia Lopes, Jose Nuno

AU - Slattery, John Martin

N1 - © The Royal Society of Chemistry 2017. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Small-angle neutron scattering experiments, supported by molecular dynamics simulations, have been performed on a range of compositions of the [C2mim]1-x[C12mim]x[Tf2N] ionic liquid mixture system. Isotopic contrast variation, through selective deuteration of both cations, has been used to assist in fitting the data to different scattering models. These data, and subsequent fitting, show that the structure of the ionic liquid mixtures changes substantially as a function of composition. Mixtures where x < 0.32 are dominated by aggregates of amphiphilic [C12mim]+ ions in the relatively polar [C2mim][Tf2N] solvent. Compositions where x > 0.32 can be described as bicontinuous, containing networks of both polar and non-polar domains, where the C12 chains of the [C12mim]+ ions percolate through the system to form a continuous non-polar sub-phase. Temperature-dependent scattering experiments suggest that there is relatively little change in bulk structure in these liquids between 20 and 60 oC. The presence of water, however, does influence some aspects of the liquid structure in a composition that is rich in [C2mim][Tf2N] (where x = 0.24).

AB - Small-angle neutron scattering experiments, supported by molecular dynamics simulations, have been performed on a range of compositions of the [C2mim]1-x[C12mim]x[Tf2N] ionic liquid mixture system. Isotopic contrast variation, through selective deuteration of both cations, has been used to assist in fitting the data to different scattering models. These data, and subsequent fitting, show that the structure of the ionic liquid mixtures changes substantially as a function of composition. Mixtures where x < 0.32 are dominated by aggregates of amphiphilic [C12mim]+ ions in the relatively polar [C2mim][Tf2N] solvent. Compositions where x > 0.32 can be described as bicontinuous, containing networks of both polar and non-polar domains, where the C12 chains of the [C12mim]+ ions percolate through the system to form a continuous non-polar sub-phase. Temperature-dependent scattering experiments suggest that there is relatively little change in bulk structure in these liquids between 20 and 60 oC. The presence of water, however, does influence some aspects of the liquid structure in a composition that is rich in [C2mim][Tf2N] (where x = 0.24).

UR - http://www.scopus.com/inward/record.url?scp=85038354424&partnerID=8YFLogxK

U2 - 10.1039/C7FD00167C

DO - 10.1039/C7FD00167C

M3 - Article

SN - 1364-5498

VL - 206

SP - 265

EP - 289

JO - FARADAY DISCUSSIONS

JF - FARADAY DISCUSSIONS

T2 - Ionic liquids: from fundamental properties to practical applications - Faraday Discussion

Y2 - 11 September 2017 through 13 September 2017

ER -