Study On Construction And Properties Of AIE Nanomaterial Based On CO₂-Involved Multicomponent Reaction

Aggregation Induced Emission(AIE)is a unique fluorescence Emission phenomenon,in which AIE active molecules have almost no fluorescence or weak fluorescence in a good solution,but emit significantly enhanced fluorescence in the Aggregation state or under solid.This unique fluorescence phenomenon enables molecules with AIE activity to effectively overcome the Aggregated-caused Quenching(ACQ)effect of traditional fluorescence molecules.As a result,AIE active materials possess incomparable advantages and potential application prospects in fluorescence imaging,fluorescence sensor,nano diagnosis and treatment,and optoelectronic devices.Polymer with AIE properties is generally prepared by active free radical polymerization,which requires toxic active initiators and heavy metal ligands or catalysts,which is not favorable for its preparation and application.Therefore,it is of great significance to develop a simple and green method for preparing polymers with AIE properties.We were proposed based on the multicomponent reaction of carbon dioxide to participate in the preparation of polymer with an AIE research train of thought,the route does not require toxic initiator or heavy metal-ligand,and with cheap substitution reaction raw materials,non-toxic CO₂ enrich and expand the application fields of an AIE polymer,for subsequent related research provides a reference template,the main research results are as follows:(1)The blue-green fluorescent nanomaterials with AIE properties based on natural polysaccharides were successfully prepared by multi-component reaction of amino,halogen and CO₂.First,the natural macromolecule chitosan was hydrolyzed to reduce its molecular weight so that it could be soluble in water solution.Then,the green luminescent tetrastyrene AIE small molecule with halogen group was synthesized.Finally,the chitosan was connected with the AIE molecule by a multi-component reaction with carbon dioxide.Compared with other polymer construction strategies,this strategy does not require any heavy metal catalyst,has high atomic availability,mild reaction conditions,and has been tested to have excellent imaging effect in cells.(2)Carboxylic functionalized green fluorescent nano self-assembly material with AIE properties was successfully prepared by the epoxy group,amino group and CO₂multi-component reaction method using oxazolidinone as the"lock"to coupling the functional monomer.First,an active fluorescent molecule of AIE containing diamino functional groups was synthesized,using lysine as the carboxyl modifier and polyethylene glycol diglycidyl ether as the hydrophilic polyethylene glycol modifier.Finally,the three-component reaction of epoxy group,amino group and carbon dioxide was catalyzed with non-toxic potassium phosphate as a base catalyst.Compared with other polymer construction strategies,this strategy does not require any heavy metal catalyst,has high atomic availability,and the reaction conditions are mild.The cell experiment results show that the synthetic AIE fluorescent assembly possesses low cytotoxicity and good cell imaging effect.(3)AIE active fluorescent nanomaterials with redox response were synthesized by microwave-assisted CO₂ multicomponent reaction.First,a red luminescent AIE molecule with diamino was synthesized,then a hydrophilic polyethylene glycol(PEG)and a redox response disulfide bond were introduced,and the multi-component reaction with carbon dioxide was accelerated by microwave to reduce the reaction time.Finally,a kind of AIE fluorescent nanomaterial with redox response and biodegradable performance was obtained.The prepared fluorescent copolymers possess potential applications in drug delivery intelligent nanocarriers and bioluminescence imaging.