Multi-responsive supramolecular organogel with a crystalline-like structure

A multi-responsive cyclodextrin-based organogel with a crystalline-like structure is first reported. An amount of β-cyclodextrin (β-CD) and lithium chloride (LiCl) was added into N,N-dimethylformamide (DMF), and the system obtained could transform instantly from a transparent solution into a gel state by introducing ethylene diamine (EDA), and then the gel could turn into another precipitate-like gel by undergoing a heating-cooling process. Among a series of aliphatic amines, only EDA was found to be able to induce the gel formation. Both the gels possess crystalline-like structures in their morphology with sheet-like layers, in a highly-ordered channel-type packing mode, which were proved by OM, SEM, XRD, and FT-IR measurements. Furthermore, the gel could respond to H(+) and Cu(2+) by transforming into an amorphous precipitate. This research may pave the way for the design of novel smart materials.