Supramolecular ionogels were prepared by self-assembly of small molecules through host-guest interaction between β-cyclodextrin (β-CD) and a room-temperature ionic liquid (IL) 3-(1-methyl-3-imidazolio)propanesulfonate-lithium bis(trifluoromethanesulfonyl)imide (MIPS-LiTFSI) which contains zwitterion MIPS. F NMR and 2D ROESYH NMR have been used to prove that only TFSI is involved in the complexation. H NMR, FT-IR, and comparative tests indicated that the electrostatic interaction between imidazole cation and TFSI anion and intermolecular hydrogen bonding between three compounds also contribute to the formation of supramolecular ionogel. Ionogels with different gel-sol phase transition temperatures can be obtained by adjusting the molar ratio between β-CD and MIPS-LiTFSI. In addition, the supramolecular ionogels composed of "channel type" structural β-CD have been constructed. The ionogel with high conductivity and low activation energy open a door to new fields for special applications.

Stimuli-responsive or "smart" soft materials have raised considerable attention due to their ability to spontaneously respond to external environmental variations and have a great potential for wide applications. Herein, a thermo/redox responsive hydrogel is facilely constructed based on a dual crosslinked matrix: the primary chemical crosslinked copolymer is composed of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and poly(ionic liquid), and the secondary physical crosslinking component is generated by the ionic coordination between iron ions and carboxyl groups in the poly(ionic liquid). The non-covalent ion coordination crosslinking is introduced into a covalently crosslinked network, which further strengthens the soft PNIPAM matrix and enhances the mechanical performances of the hydrogels. The excellent thermosensitivity of PNIPAM and the good conductive property of poly(ionic liquid) provide the hydrogel with an attractive performance as a thermo-responsive switch. Moreover, the trapped iron ions in the network endow the hydrogels with redox-responsiveness, which could be reversibly chemically oxidized and reduced. The mechanical strength of hydrogels could also be tuned by the crosslinked capacity of iron ions within the gel matrix between the strong binding of the oxidized state (Fe3+) and poor coordination of the reduced state (Fe2+). These stimuli-responsive hydrogels have the potential to be used as smart materials for stimuli-responsive devices.

We herein report a smart amphiphilic supramolecular complex ([MimA-EDA-MimA]@[DBS]) with stimuli-responsive self-assembly, constructed by 3-(3-formyl-4-hydroxybenzyl)-1-methylimidazolium chloride (MimACl), sodium dodecyl benzene sulfonate (SDBS), and ethylenediamine (EDA). The self-assembly of [MimA-EDA-MimA]@[DBS] shows triple-sensitivities in response to pH, concentration, and salt. At a low pH, only micelles are formed, which can transform into vesicles spontaneously when the pH increases to 11.8. Vesicles can gradually fuse into vesicle clusters and elongated assemblies with increasing concentration of [MimA-EDA-MimA]@[DBS]. Chainlike aggregates, ringlike aggregates, or giant vesicles can be formed by adding inorganic salts (i.e., NaCl and NaNO), which could be derived from the membrane fusion of vesicles. The noncovalent interactions, including π-π stacking, hydrogen bonding, and electrostatic interactions, were found to be responsible for the topology evolution of assemblies. Thus, it provides an opportunity to construct smart materials through the regulation of the role of noncovalent interactions in self-assembly.

Supramolecular thermotropic ionic liquid crystals (ILCs) with hexagonal and lamellar phases were fabricated by the self-assembly of zwitterionic ionic liquids, which were formed by 3-(1-alkyl-3-imidazolio) propanesulfonate with different alkyl chain lengths C n IPS (n = 12, 14, 16) and 3,4,5-tris(dodecyloxy)benzoic acid (TDBA) based on intermolecular electrostatic interactions. The phase behaviors of ILCs were investigated by differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), and polarized optical microscopy (POM). The highly ordered and well-defined microstructure of ILCs can be considered to be proton pathways and to radically improve the ionic conductivity, suggesting the induction of proton conduction through a hopping mechanism.