Preparation And Properties Of Modified Photoluminescent Benzoic Acid Rare Earth Complexes

In the first part of this paper,the preparation and properties of benzoic acid organic rare earth complexes coated with silicon dioxide with good luminescent properties and high heat resistance were studied.Firstly,five organic rare earth complexes were synthesized by the coordination of benzoic acid ligands with rare earth ions.Secondly,five organic rare earth complexes were coated with silicon dioxide which had good transparency producted by hydrolysis and condensation of tetraethyl orthosilicate(TEOS).Finally,using ethanol as solvent,the effects of reaction temperature,stirring time,volume of ammonia,TEOS and dispersing solvent on the preparation of silica microspheres containing different rare earth complexes were studied.The transform infrared(FT-IR),scanning electron microscopy(SEM),thermogravimetric analysis(TG)and fluorescence spectroscopy were used to characterize the surface morphology,structure,thermal and luminescent properties of the samples.The benzoic acid organic rare earth complexes coated with silicon dioxide with good luminescent properties and high heat resistance were obtained.These research results are of great significance to broaden the application fields of benzoic acid organic rare earth complexes.The second part of this paper is the study of preparation and properties of binuclear organic rare earth complexes with multi-branched benzoic acid.Firstly,using 1,3,5-benzotriacyl chloride and glycolic acid as raw materials,the multi-branched benzoic acid ligand was synthesized by functional group protection,deprotection and other organic synthesis techniques.Secondly,single or multiple rare earth ions were selected as the center to prepare the mononuclear and binuclear organic rare earth complexes of multi-branched benzoic acid.Finally,FT-IR,SEM,TG and fluorescence spectroscopy were used to study the structure,morphology,thermal stability and fluorescence properties of the binuclear organic rare earth complexes with multi-branched benzoic acid.The results show that the binuclear organic rare earth complexes of multi-branched benzoic acid have been prepared successfully,the thermal stability and luminescent properties are improved.The research results are of great meaning for reducing production costs and saving rare earth resources.Finally,we look forward to the application of rare earth complexes.The coated rare earth complexes can be produced in large quantities for melt spinning.The silica surface of the coated rare earth complex can be modified,grafting or adding other functional groups to make it possess other properties.These studies are theoretically feasible.