Cucurbit[8]uril mediated ultralong purely organic phosphorescence and excellent mechanical strength performance in double-network supramolecular hydrogels

Abstract Room-temperature phosphorescence (RTP) hydrogels have been considered as one of the ideal candidates for fabrication of artificial soft functional materials. Herein, we report a rational design strategy for the construction of double-network (DN) supramolecular hydrogels with RTP emission via in situ copolymerization of acrylamide and supramolecular complexes in the presence of polyvinyl alcohol (PVA) skeleton. The supramolecular complex was a stable 1:2 inclusion complex, prepared by the host-guest interaction between cucurbit[8]uril (CB [8]) and allyl-modified 4-(4-bromophenyl)pyridin-1-ium bromide (ABP) phosphor. The supramolecular complex (CB [8]/ABP) not only exhibits excellent RTP behaviors, but also can act as a crosslinker to connect the polyacrylamide chains, thus enhancing the mechanical strength of the constructed DN supramolecular hydrogels. Therefore, excellent RTP supramolecular hydrogels with extremely stretchable and tough capability are obtained. Moreover, the DN supramolecular hydrogels show a remarkable self-healing ability owing to the host-guest complexation interaction and hydrogen bond interaction.