A cross-linked supramolecular polymer network gel is designed and prepared, which shows reversible gel-sol transitions induced by changes in pH, temperature, cation concentration, and metal co-ordination. The gel pore size is controlled by the amount of cross-linker added to the system, and the material can be molded into shape-persistent, free-standing objects with elastic behavior. These features are all due to the dynamically reversible host-guest complexation and good mechanical properties of the cross-linked polymer network. No single organogel has previously been reported to possess all of these features, making this supramolecular gel an unprecedentedly intelligent soft material.

Automatic repair: a polymer with pendent dibenzo[24]crown-8 units (purple in picture) was cross-linked by two bisammonium salts (green) to form two supramolecular gels based on host-guest interactions. These two gels are stimuli-responsive materials that respond to changes of the pH value and are also self-healing materials, as can be seen by eye and as evidenced by rheological data.

Automatische Reparatur: Ein Polymer mit Dibenzo[24]Krone‐8‐Einheiten (violett im Bild) als Seitenarmen wurde durch zwei Bisammoniumsalze (grün) unter Nutzung von Wirt‐Gast‐Wechselwirkungen zu supramolekularen Gelen verknüpft. Beide Gele sind Materialien, die auf externe Auslöser reagieren, hier auf Änderungen des pH‐Wertes, und sind zudem selbstheilend, wie für das Auge sichtbar ist und mit Rheologie‐Messungen gezeigt wurde.

A crown ether appended super gelator is designed and synthesized. It can gel a variety of organic solvents and shows excellent gelation properties with both low critical gelation concentration and short gelation time. Due to the introduction of the crown ether moiety and a secondary ammonium unit, the supramolecular gels show reversible gel-sol transitions. The supramolecular gels can also be molded into shape-persistent and free-standing objects.

by judiciously adjusting the structure of ILs. ILs have been intensively studied as a "green" alternative to organic solvents for synthesis, catalysis, extraction, and separation. [2] They are also safe and versatile electrolytes for electrochemistry and energy-related applications. [3] However, their viscosities are generally two or three orders of magnitude higher than those of conventional organic solvents (molecular liquids), which inevitably lead to handling difficulties (e.g., infiltration, decantation, and dissolution), low reaction rates, competitive unimolecular side reactions, sluggish ionic transport, and significantly reduced ionic conductivity. [4] For the potential application of ILs, such high viscosities have to be deliberately avoided by choosing alternative anions such as bis (trifluoromethanesulfonimide) (TFSI − ) and dicyanamide anions with high charge delocalization [4b,5] or introducing ether groups that pack less efficiently and provide more available free volume to enable low viscosity. [6] Nevertheless, the disadvantageous high viscosities of ILs can become advantageous for special applications that require viscous materials, such as adhesion, sealing, and gelation. [7] Particularly, adhesion is the attraction between two different condensed phases when they are in contact to construct a robust joint. Adhesion involves not only the molecular interactions at the interface of two individual surfaces but also the energy within the deformed material when pulling them apart. Adhesives have been acknowledged as indispensable chemicals in daily life and in many industries ranging from packaging, labeling, housing construction, and automobile manufacturing to soft robots, wearable devices, and aerospace. [7a,b,8] Along with conventional resins and gum-based adhesives, many musselinspired and catechol-based polymeric materials had been developed as modern adhesives in the past. [9] Nevertheless, they possess inherent drawbacks such as irreversible oxidizing crosslinking, tedious synthesis, and poor cycling performance. [10] We recently reported a series of noncatechol adhesive materials produced by water-triggered supramolecular polymerization of crown ether-containing monomers, but the synthesis of such specific monomers involves complicated functionalization, which is difficult to scale up. [11] The presence of water in these supramolecular adhesives also becomes an obvious disadvantage as they cannot bear ultra-high vacuum adhesion.Adhesive materials have wide applications in diverse fields, but the development of a novel and multipurpose adhesive is a great challenge. This study demonstrates that conventional poly(ionic liquid)s (PILs) can be designed as highly efficient adhesives by simply introducing alkoxy moieties into the cationic backbone of PILs containing bis(trifluoromethanesulfonimide) (TFSI − ) anions. The incorporated flexible alkoxy chain not only reduces the glass transition temperature of PILs but also endows these materials with strong hydrogen bonding interactions, w...