Supramolecular metallacyclic hydrogels with tunable strength switched by host–guest interactions. Issue 4 (13th December 2019)

• Record Type: Journal Article
• Authors: Zhang, Chang-Wei; Jiang, Shu-Ting; Zheng, Wei; Ji, Tan; Huo, Gui-Fei; Yin, Guang-Qiang; Li, Xiaopeng; Liao, Xiaojuan
• Is Part Of: Polymer chemistry. Volume 11:Issue 4(2020)
• Page Start: 882
• Page End: 888
• Publication Date: 2019-12-13
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c9py01471c
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : A new family of supramolecular hydrogels with tunable strength was successfully constructed through a combination of coordination-driven self-assembly, post-assembly polymerization and host–guest interactions. Abstract : Herein, we present the construction of a new type of supramolecular hydrogel with tunable strength switched by host–guest interactions via a hierarchical self-assembly strategy. Firstly, through coordination-driven self-assembly, a rhomboidal metallacycle H with two crown ether units and two chain transfer agent (CTA) units was constructed. The successful construction of metallacycle H was confirmed via multiple NMR and MS spectra. Subsequently, two poly( N -isopropylacrylamide) (PNIPAM) chains were introduced into the metallacycle through reversible addition–fragmentation chain transfer polymerization of N -isopropylacrylamide (NIPAM) monomers. The obtained PNIPAM chains can form hydrogels upon being mixed with water. With the addition of the ditopic guest G to the system, a new polymer network was formed via host–guest interactions between the crown ether units and the guest. Interestingly, the strength of the hydrogel increased in the presence of the ditopic guest G and decreased with the addition of KPF6 as a competitive guest.