Structure-property and bioimaging application of the difunctional polyarylene ether nitrile with AIEE feature and carboxyl group

A series of AIEE and carboxyl difunctional polyarylene ether nitrile (PEN) were synthesized via stepwise polymerization. Their structure-property and bioimaging application were studied. The synthesized PEN exhibited excellent thermal resistance with thermal decomposition temperature beyond 380 degrees C and glass transition temperature over 192 degrees C. Incorporation of AIEgen imparted PEN with a higher quantum yield (36%), and emission peak redshift from weak blue to bright cyan region under solid state. The soluble polymer also can be processed into flexible films by casting method with good mechanical property and strong fluorescent emitting. Under the synergistic action of difunctional segments, PEN was endowed with the assembled fluorescent polymeric nanoparticles (FPNs) though the coordination effect between metal ions and carboxyl group with much higher emission efficiently. Finally, based on the well biocompatible and hydrophilia of difunctional PEN, the obtained FPNs revealed the cellular bioimaging application. The current work lays the foundation for PEN perform as a high-performance engineering polymer with fluorescent perform in the development of optical applications.