Synthesis And Luminescent Properties Of Tetraphenylethene (TPE) Derivatives Based Lanthanides Organic Composite Materials

Rare earth materials were widely used in optical materials because of their unique physical and chemical properties,especially the fluorescence properties of some rare earth elements are stable and the fluorescence wavelengths of different rare earth elements are obviously different and have good differentiation.When rare earth elements exist in the form of ions or some inorganic salts,the fluorescence intensity is relatively weak,so sensitizers are often introduced to enhance the fluorescence intensity.β-diketone derivatives are commonly used sensitizers that significantly enhance the fluorescence emission of europium ions,but on the other hand,similar to most conventional organic fluorescent materials,have aggregation-induced quenching(ACQ),which usually results in a substantial reduction in fluorescence intensity or even quenching in the aggregated state.With the continuous development and research of aggregation-induced luminescence(AIE)fluorescent materials represented by TPE derivatives,new ideas and directions have been provided to solve the drawbacks caused by ACQ effect of most fluorescent materials.Due to the different fluorescence properties of TPE derivatives and β-diketone,complex fluorescence emission systems with different energy transfer pathways can be constructed by utilizing the energy transfer of TPE derivatives and β-diketone derivatives to rare earth ions in different systems.Based on this idea,two kinds of rare earth-TPE derivatives composite fluorescent materials were designed and synthesized in this paper:sodium alginate fluorescent gel and EuVO4 nano fluorescent material.In Chapter 2,we synthesized a sodium alginate hydrogel with rare earth complex-TPE derivatives and achieved white light emission in room temperature aqueous solution.First,we discuss the possible energy transfer pathways in the system.Besides,we determined the fluorescence properties of the hydrogel in different water-soluble solvents,and found that it would produce a large difference in fluorescence in dimethyl sulfoxide(DMSO)solvent.In addition,because alginate has excellent biocompatibility and low toxicity,the construction of the composite system has certain reference value for the development of low toxicity and biofriendly fluorescent materials.In Chapter 3,we prepared and studied two kinds of composite fluorescent nanomaterials.Firstly,EuVO4 was used as inorganic nanomaterials and the surface was modified with sodium polystyrene sulfonate(PSS).Furthermore,the ionic TPE derivative 4-methyl-1-(4-(1,2,2-triphenylvinylbenzyl)pyridine-1-ammonium bromide(TPE-Py-Me),denoted as TPE-Py-Me@PSS@EuVO4 nanoparticles,was synthesized in this material.The molecular structure of TPE derivatives was restricted by the molecular chain of PSS,and the fluorescence emission of TPE derivatives was realized in good solvent,and the energy transfer of TPE derivatives to EuVO4 was realized.On the basis of the above products,in order to further enhance the fluorescence intensity of europium,a β-diketone derivative ABM,written as TPE-Py-Me@PSS/ABM@EuVO4 nanoparticles,was introduced into the system.After the synthesis of the two products,we determined their structure and composition by XPS,TGA,IR and other characterization methods,and determined the possible energy transfer pathways in the system by measuring the energy levels of different components,and characterized their fluorescence transfer efficiency by fluorescence quantum yield and fluorescence lifetime.In addition,we found that the two products can respectively perform characteristic responses to organic amines and organic acids.Based on this,we further measured the corresponding data and studied the mechanism of the responses.