Influence of Monomers’ Structure on the Assembly and Material Property of Pillar[5]arene‐Based Supramolecular Polymer Gels

Abstract

Main observation and conclusionPillar[5]arene‐based supramolecular polymer gels (SPGs) show broad application prospects. To investigate the influence of the supramolecular monomers’ structure on the assembly and properties of corresponding pillar[5]arene‐based SPGs, a series of monomers based on different functionalized pillar[5]arene derivatives with various structures were synthesized. There are per‐methylated pillar[5]arene (H1), bromobutane‐functionalized pillar[5]arene (H2), 4‐hydroxybenzaldehyde‐functionalized pillar[5]arene (H3), ethyl thioglycolate‐functionalized pillar[5]arene (H4), thioacetylhydrazine‐functionalized pillar[5]arene (H5), bola‐type bis‐pillar[5]arene (H6) and tripodal‐type tri‐pillar[5]arene (H7). Meanwhile, a neutral tripodal‐guest TG was also employed to co‐assemble with these pillar[5]arene‐based monomers by host‐guest interactions. As a result, under the same conditions (10%, DMSO‐H2O, w/v, 10 mg·mL–1 = 1%), H1 and H2 cannot assemble into SPGs with TG. Interestingly, mono‐p[5] derivatives H3—H5 could assemble into SPGs with TG. More importantly, bis‐p[5] H6 and tri‐p[5] H7 could assemble into supramolecular polymer network gel (SPNG) and supramolecular polymer organic framework gel (SOFG) with TG, respectively. These gels all show blue aggregation‐induced emission (AIE) properties. Among these SPGs, the SPNG shows the best viscoelastic behavior and self‐healing properties. The result is attributed to the flexible network structure of SPNGs. In addition, the xerogels of SOFG and SPNG have shown nice adsorption and separation properties for organic dyes in water solution.