Fabrication of novel supramolecular hydrogels with high mechanical strength and adjustable thermosensitivity.

An effective strategy was developed to fabricate the supramolecular hydrogels with high mechanical strength and adjustable thermosensitivity in aqueous systems, in which physical hydrogel precursors were first formed by the inclusion complexation of Pluronic F68/poly(epsilon-caprolactone) block copolymer end-capped with acryloyl groups with alpha-cyclodextrin (alpha-CD) and subsequently in situ UV photo-cross-linking was carried out. In this way, strong supramolecular hydrogels with elastic moduli greater than 100 000 Pa could be created, which is an order of magnitude higher than that previously achieved with related supramolecular hydrogels. Moreover, the stimuli-responsive property of these hydrogels could be tailored by changing the molar feed ratio of alpha-CD to the macromer. By X-ray diffraction and thermogravimetric analyses, the polypseudorotaxane structure of the inclusion complexes in as-obtained hydrogels was confirmed.