Precise synthesis of polyrotaxane and preparation of supramolecular materials based on its mobility

Precision synthesis of linear oligorotaxanes and polyrotaxanes achieving well-defined positions and numbers of cyclic components on the axle

“…In addition, the reversibility of the assembly process based on dynamic covalent imine bonds affords a thermodynamically stable species, where the ammonium cations interact with oligoether-type macrocycles without any macrocyclic defects. Hence, the synthetic strategy provided various oligorotaxanes (2), including [3], [4], [5], [7], and [11]rotaxanes, with well-defined numbers of macrocycles. In 2012, Stoddart et al further improved the methodology for oligorotaxane synthesis.…”

“…behavior has resulted in extensive investigations into polymeric rotaxane structures. 10,11 In particular, since Harada et al reported effective synthetic procedures for polyrotaxanes consisting of poly(ethylene glycol) and cyclodextrins, [12][13][14][15] numerous polyrotaxanes have been developed containing various types of cyclic and axle molecules. [16][17][18][19][20][21][22] These polyrotaxanes have unique functions based on the shuttling of macrocycles induced by thermal and chemical stimuli.…”

Supramolecular Hydrogels Based on Cyclodextrins: Progress and Perspectives

“…Originally developed as molecular ratchets and shuttles, the CDs stringed on polymer chain have a unique ability to slide on the chain at low inclusion ratios in response to sheer strain and various stimuli. Polyrotaxane based hydrogels usually consists of CDs threaded on a polymer chain capped by stopper molecules at both ends to prevent de‐threading of CDs [29] . Crosslinks required for hydrogel formation are introduced in these polymer chains by either covalently connecting the stopper molecules, interconnecting CDs on different polymer chains via additional linker molecules, or hydrophilic interactions of CDs [30] (see Figure 2a).…”

“…Polyrotaxane based hydrogels usually consists of CDs threaded on a polymer chain capped by stopper molecules at both ends to prevent de-threading of CDs. [29] Crosslinks required for hydrogel formation are introduced in these polymer chains by either covalently connecting the stopper molecules, interconnecting CDs on different polymer chains via additional linker molecules, or hydrophilic interactions of CDs [30] (see Figure 2a). The resulting hydrogels are also called ring slide gels as the CDs can move on the polymer chain providing it superior mechanical and structural properties compared to other supramolecular methods [31] (see Figure 2b).…”

“…c) The reversible nature of the host-guest inclusion complexes provides shear thinning properties and aids the injectability of the hydrogel [40][41]. d) The elastic properties of the hydrogel are enhanced via non-covalent crosslinking giving the material remarkable stretchability and strain recovery [29][30]. e) The dynamic stiffness and high water content of the hydrogels may be used for bio-imaging and studying cell behaviour since those characteristics mimic extracellular matrices [33,43,59].…”