Elstone Naomi S, Shaw Emily V, Shimizu Karina, Lai Joshua, Demé Bruno, Lane Paul D, Costen Matthew L, McKendrick Kenneth G, Youngs Sarah, Rogers Sarah E, Canongia Lopes Jose N, Bruce Duncan W, Slattery John M
Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049 001, Portugal.
Faraday Discuss. 2024 Oct 25;253(0):55-78. doi: 10.1039/d4fd00047a.
As part of an ongoing study of the structure and properties of mixtures of ionic liquids in which one component has a hydrocarbon chain and the other a semiperfluorocarbon chain, we now report a study of the mixtures [CMIM][CMIM-F][TfN], [CMIM][CMIM-F][TfN] and [CMIM][CMIM-F][TfN], where [CMIM][TfN] is 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide, [CMIM][TfN] is 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [CMIM-F][TfN] is 1-(1,1,2,2-perfluorooctyl)-3-methylimidizolium bis(trifluoromethylsulfonyl)imide and [CMIM-F][TfN] is 1-(1,1,2,2-perfluorodecyl)-3-methylimidizolium bis(trifluoromethylsulfonyl)imide. The mixtures were investigated using small-angle X-ray (SAXS) and neutron (SANS) scattering complemented by molecular dynamics simulations (with viscosity and surface tension measurements also possible for the mixtures [CMIM][CMIM-F][TfN]). Unlike previous studies of [CMIM][CMIM-F][TfN], where no strong evidence of alkyl/fluoroalkyl chain segregation or triphilic behaviour was seen (Elstone , , 2023, 127, 7394-7407), these new mixtures show the formation of small aggregates of varying sizes of each component, even though all were co-miscible across the full range of compositions. Thus, while a clear polar non-polar peak (PNPP) was observed at large or small values of , at intermediate compositions the small-angle neutron scattering at low was dominated by scattering from these small aggregates, while at other compositions, there was little or no evidence of the PNPP. The origins of this behaviour are discussed in terms of inter-chain interactions.
作为对离子液体混合物结构和性质正在进行的研究的一部分，其中一种组分具有烃链，另一种具有半全氟碳链，我们现在报告对混合物[CMIM][CMIM - F][TfN]、[CMIM][CMIM - F][TfN]和[CMIM][CMIM - F][TfN]的研究，其中[CMIM][TfN]是1 - 甲基 - 3 - 辛基咪唑鎓双（三氟甲基磺酰）亚胺，[CMIM][TfN]是1 - 癸基 - 3 - 甲基咪唑鎓双（三氟甲基磺酰）亚胺，[CMIM - F][TfN]是1 - （1,1,2,2 - 全氟辛基） - 3 - 甲基咪唑鎓双（三氟甲基磺酰）亚胺，[CMIM - F][TfN]是1 - （1,1,2,2 - 全氟癸基） - 3 - 甲基咪唑鎓双（三氟甲基磺酰）亚胺。使用小角X射线（SAXS）和中子（SANS）散射对这些混合物进行了研究，并辅以分子动力学模拟（对于混合物[CMIM][CMIM - F][TfN]也可以进行粘度和表面张力测量）。与之前对[CMIM][CMIM - F][TfN]的研究不同，在之前的研究中未发现烷基/氟烷基链分离或双亲性行为的有力证据（Elstone，，2023，127，7394 - 7407）。这些新的混合物显示出每种组分形成了大小不同的小聚集体，尽管所有混合物在整个组成范围内都是互溶的。因此，虽然在大或小的 值处观察到了明显的极性 - 非极性峰（PNPP），但在中间组成时，低 下的小角中子散射主要由这些小聚集体的散射主导，而在其他组成时，几乎没有或没有PNPP的证据。根据链间相互作用讨论了这种行为的起源。
