Construction Of AIE-active Polymeric Materials Based On Multicomponment Reactions And Their Applications

Owing to their well designability,visualization,ease of operation,fluorescent nanomaterials play an increasingly important role in biosensors and biomedicne.However,the tradiational fluorescent nanomaterials also have some drawbacks that could not be ignored.For instance,the inorganic semiconductor quantum dots(QDs)are composited with heavy metal ions,and can be accumulated in body for a long term.These inorganic QDs could easily release free heavy metal ions and result in obvious toxicity to living organisms.The fluorescent materials based on conventional organic dyes could overcome the toxicity of inorganic QDs,however,they also display aggregation-caused quenching(ACQ)effect when they were used in biological systems owing to their hydrophobicity and aggregation in aqueous solution.Therefore,the development of novel fluorescent materials with good biocompatibility and excellent optical properties should be of critical importance for their biomedical applications.The aggregation induced luminescence(AIE)phenonmenon was first discovered and purposed by Prof.Tang in 2001.The AIE-active molecules or materials will emit more efficient in aggregate or solid state while almost no fluorescence or weak fluorescence in highly dispersed state.Therefore,the AIE-active molecules or materials should be promising candidates for the preparation of materials with intensive fluorescence.However,there are still some challenges required to be overcome for the biomedical applications of AIE-active molecules.On the one hand,it needs to improve the dispersibility and biocompatibility of the AIE-active materials.On the other hand,it is desirable to develop highly efficient strategies for fabrication of AIE-active fluorescent materials.In this thesis,we purposed the fabrication of AIE-active fluorescent materials through multi-component reactions based on our previous research background.The main contexts of this thesis could be divided into the following parts:1.In chapter 2,we fabricated hydrophilic poly(AA-AEMA))through the RAFT polymerization.Then the hydrophobic AIE-active dye was conjugated onto the poly(AA-AEMA)through the Biginelli reaction.The obtained poly(AA-AEMA-TPE)displays amphiphilicity and could self-assemble into the fluorescent nanoparticles under in aqueous solution.The resultant self-assemblies shows high water dispersibility,good biocompatibility and can be utilized for cell imaging.2.In chapter 3,we synthesized the AIE-active TPE-poly(AEMA-co-MPC)through a "one-pot" strategy that combining the Biginelli reaction and RAFT polymerization.The obtained product(TPE-poly(AEMA-co-MPC))exhibits excellent biocompatibility,great dispersibility,and an obvious AIE feature.3.In chapter 4,we reported the synthesis of AIE-active molecules(2-(4-pyridin)-1,4,5-triphenylimidazole)through the Debus-Radziszewski reaction using the non-fluoresence precursors.The obtained fluorescence molecules display outstanding AIE phenomenon.Moreover,the wavelengths of these synthesized AIE dyes could be adjusted in some extent through using different precursors.In chapter 5,we synthesized the AIE-active FONs(poly(PEGMA-co-ATIPB)FONs)via a one-pot strategy,which combines Debus-Radziszewski reaction)and RAFT polymerization simultaneously.Based on the results,we demonstrated that the resultant AIE-active FONs could not only display excellent AIE property but also possess great biocompatibility and dispersibility.