As a marriage of polymeric hydrogels and fluorescent materials, fluorescent polymeric hydrogels (FPHs) potentially integrate the merits of both materials, including intrinsic soft wet nature, tissue-like mechanical strength, biocompatibility, biomimetic self-healing feature, facilely tailored structure, and responsive fluorescence. Thus FPHs showed wide application in many fields such as sensing, imaging, displaying and anti-counterfeiting over the past decades.  

Among them, the FPHs with aggregation-induced emission (AIE) nature have drawn great attention due to that the AIE-active FPHs bear many excellent properties and thus represent a promising category of luminescent materials. 

Based on previous findings on AIE-active FPHs, Prof. CHEN Tao and colleagues at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS), systematically summarized the recent progress in this young but flourishing research area, with particular focus on the design and preparation of AIE-active FPHs. The study was published in Aggregate. 

The researchers elaborated the development significance and performance advantages of AIE-active FPHs.  

In addition, they put great emphasis on the synthesis strategy, which are classified as physical doping, covalent bonding, and supramolecular polymerization of organic AIEgens into crosslinked polymer networks. Each synthesis strategy was illustrated with a series of examples and case studies, and their practical or potential applications were demonstrated. 

Moreover, the researchers discussed the challenges and future perspectives in this field, including the exploration of simple and easy-to-operate synthetic methods, fabrication of multi-functional AIE-active FPHs, development of robust red-light-emitting FPHs, as well as systems with emission spectrum far more into the near-IR region.  

This review is expected to shed light on the further research in this field and arouse interests of researchers with various backgrounds thus trigger new opportunities.

The schemetic illustration of the synthesis strategies of AIE-active FPHs (Image by NIMTE)