Structural evolution of imidazolium-based poly (ionic liquid) assemblies during solvent evaporation

Abstract

The fabrication of polymer-based assemblies with molecular packing at different length scales has recently received a great deal of attention due to their promising potentials to produce functional, nanostructured materials [1][2][3][4][5]. Amphiphilic block or graft copolymers are common candidates for such self-assembled organization and ordering in nano-, and mesoscale. This self-assembly behavior is normally driven by a variety of covalent interaction and noncovalent interactions (e.g., electrostatics, hydrogen bonding, and van der Waals interactions). In terms of morphology versatility, copolymers with amphiphilic characteristic can self-assemble into various structures such as micelles, vesicles in their aqueous or organic solution, and lamellar, hexagonally packed cylinder, spherical, and gyroid structures in their solid bulk [6][7][8][9][10][11]. The size and morphology of these ordered structures are dependent on the composition, molecular weight, processing characteristics, especially on the balance between the hydrophobic domains and the hydrophilic domains. Ionic liquids (ILs) have been paid increasingly attention because of their unique properties such as non-volatility, nonflammability, high thermal stability and tunable solvation interactions [12]. Those unique properties can be tuned by modifying the combination of cations and anions, displaying a 'designer -]/DMF mixture shows a lamellar structure with a tiny minority of bicontinuous cubic phase that disappears instead in the corresponding dried samples caused by the decrease in space-filling requirement for alkyl chains arrangement. For poly [C 16 VIm + ][PF 6 -], there is almost no change in inner structures with solvent evaporation except a more ordered lamellar morphology observed in the dried sample. Notably, an interdigitated packing of alkyl tails dominates the lamellar sheets for all dried PIL samples. These results indicate that the design and fabrication of PIL assemblies with ordered structures can be achieved by simply changing counteranion and solvent content, which offers a feasible approach for engineering PIL-based nano-scale functional materials.

Nonmonotonic Influence of Size of Quaternary Ammonium Countercations on Micromorphology, Polarization, and Electroresponse of Anionic Poly(ionic liquid)s

“…As shown in Figure b, P­[STFSI]­[N1111] displays one broad amorphous peak at 17.0° and a sharp XRD peak at 5.4°. The sharp peak indicates that there is an increase of interplanar and intraplanar ordered packing of P­[STFSI] + chains or semicrystalline structure in P­[STFSI]­[N1111] as shown by the bottom inset in Figure b. , P­[STFSI]­[N2222] only displays one broad peak at 15.2°, indicating a relatively uniform amorphous structure as shown by the middle inset in Figure b . P­[STFSI]­[N3333] displays two broad peaks at 11.3° and 20.9°.…”

Experimental and in silico insights: interaction of dimethyl sulphoxide with 1-hexyl-2-methyl imidazolium bromide/1-octyl-2-methyl imidazolium bromide at different temperatures

“…Several discernible peaks provided evidence for an imidazolium ring, including N-H stretching at 3397.96 cm to the presence of alkyl chain groups. [42][43][44] Numerous earlier studies revealed that the absence of the C-Br stretching absorbance band in the IR spectra for the absorption of singleelement anions Br was caused by the synthesis of the imidazolium salt and the lack of bond vibration. [45][46][47]…”