Nanomaterials have emerged as an amazing class of materials that consists of a broad spectrum of materials with at least one dimension in the range of 1 to 100 nm....

It is highly desirable to integrate the CO 2 solubility benefits of ionic liquids (ILs) in polymeric membrane systems for effective CO 2 separations. Herein, we are exclusively exploring a series of four novel imidazolium-mediated Tröger’s base (TB)-containing ionene polymers for enhanced CO 2 separation. The two diimidazole-functionalized Tröger’s base monomers synthesized from “ortho”- and “para”-substituted imidazole anilines were polymerized with equimolar amounts of two different aromatic and aliphatic comonomers (α,α′-dichloro- p -xylene and 1,10-dibromodecane, respectively) via Menshutkin reactions to obtain four respective ionene polymers ([Im-TB( o & p )-Xy][Cl] and ([Im-TB( o & p )-C 10 ][Br], respectively). The resulting ionene polymers having halide anions were exchanged with [Tf 2 N] − anions, yielding a novel Tröger’s base material [Im-TB(x)-R][Tf 2 N] or “Im-TB-Ionenes”. The structural and physical properties as well as the gas separation behaviors of the copolymers of aromatic and aliphatic Im-TB-Ionenes have been extensively investigated with respect to the regiochemistry of imidazolium groups at the ortho and para positions of the TB unit. The imidazolium-mediated TB-Ionenes showed high CO 2 solubility and hence an excellent CO 2 /CH 4 permselectivity of 82.5. The Im-TB-Ionenes also displayed good thermal and mechanical stabilities.

Three new isomeric 6FDA-based polyimide-ionenes, with imidazolium moieties and varying regiochemistry (para-, meta-, and ortho- connectivity), and composites with three different ionic liquids (ILs) have been developed as gas separation membranes. The structural-property relationships and gas separation behaviors of the newly developed 6FDA polyimide-ionene + IL composites have been extensively studied. All the 6FDA-based polyimide-ionenes exhibited good compatibility with the ILs and produced homogeneous hybrid membranes with the high thermal stability of ~380 °C. Particularly, [6FDA I4A pXy][Tf2N] ionene + IL hybrids having [C4mim][Tf2N] and [Bnmim][Tf2N] ILs offered mechanically stable matrixes with high CO2 affinity. The permeability of CO2 was increased by factors of 2 and 3 for C4mim and Bnmim hybrids (2.15 to 6.32 barrers), respectively, compared to the neat [6FDA I4A pXy][Tf2N] without sacrificing their permselectivity for CO2/CH4 and CO2/N2 gas pairs.