A novel supramolecular graft copolymer via cucurbit[8]uril-based complexation and its self-assembly

A novel supramolecular graft copolymer (SGP) composed of viologen-containing copolymer (P(DMA-co-diEV)) as the main chain and Np ended PNIPAM (Np-PNIPAm) as the grafts is prepared (DMA: N,N-dimethylacryamide, diEV: ethylviologen dimer, Np: naphthalene, PNIPAM: poly(N-isopropylacrylamide)). The grafting is based on the triple complexation among a host of cucurbit[8]uril (CB[8]) and two guests of diEV and Np, which is characterized by UV–vis spectra and ITC. Temperature sensitive property of PNIPAm moiety allows SGP to self-assemble into non-covalently connected micelle (NCCM) at high temperature. The micelles are sensitive to reducing agents, for example Na2S2O3, which breaks the current inclusion complex pair and induces aggregation.

Graphical abstractA supramolecular graft copolymer has been prepared via inclusion complexation of CB[8] and two different guests. The structure forms non-covalently connected micelles at 40 °C with a PNIPAM core and a PDMA shell, which can be dissociated after addition of reducing reagent.Figure optionsDownload full-size imageDownload as PowerPoint slide