Preparation And Properties Of Nano Ag Doped NaYF₄-PLGA-gelatin Composite Fiber With Rare Earth

Rare-earth doped up-conversion luminescent materials have great potential and advantages in biological inspection,medical imaging and solar cells due to their unique photochemical stability,wide luminescence coverage and long fluorescent life,but their luminescence intensity and efficiency are not high,which greatly limit their applications.Traditional coating is a common synthesis method of composite materials,but its reaction conditions are harsh and the coating thickness is difficult to control.Electrostatic spinning fiber membrane with its excellent mechanical properties,biocompatibility and degradability and specific surface area,and many other advantages widely research,especially biomedical,so the preparation methods of new type-electrostatic spinning in combination,to study the luminescent material luminous intensity on conversion and the performance of fiber membrane is valuable.This paper is as follows:NaYF₄ up-conversion nanoparticles with cylindrical morphology and hexagonal phase structure were prepared by hydrothermal method.When the doping ratios of activator Er and sensitizer Yb were 2%and 20%,respectively,the optical performance of Na YF₄ nanoparticles was excellent.Subsequently,the Na YF₄-PLGA-gelatin electrospun fiber membranes with different content of Na YF₄ nanoparticles were prepared by electrostatic spinning.There are no beads,nodes,and tensile defects on the surface of electrospun fiber,the fiber diameter increases gradually,the porosity decreases slightly,the water absorption is high,the protein adsorption value is small and has nothing to do with the content of doped particles,and the mechanical properties are improved.When the content of Na YF₄ was 5mg/m L,the luminescence intensity of the fiber membrane was the highest.The weight loss rate of doped particles is fast in the early stage and slow in the late stage,and the degradation rate of the fiber film is accelerated when the content of doped particles reaches a certain value.Ag nanoparticles were prepared by chemical reduction method.Ag-Na YF₄-PLGA-gelatine fiber membranes with different content of Ag nanoparticles were prepared by metal surface plasma effect.With the increase of Ag sol content,the fiber diameter gradually increased,the surface gradually became rough,and the porosity gradually began to decline.When the content of Ag sol doped was 2m L,the luminescence intensity and fluorescence life were good.Compared with undoped Ag-sol,Ag-Na YF₄-PLGA-gelatine fiber membrane increased water absorption,decreased protein adsorption,and improved strength and toughness of the fiber membrane.With the increase of Ag sol doping content,the degradation rate of fiber is accelerated..