Studies On The Preparation And Properties Of The Rare Earth Doped Functional Composite

In recent years,the rare earth materials have attracted widespread attention because of their unique advantages,such as light,electricity,magnetism and so on.China is a large agricultural country,so agricultural film production and consumption are in the forefront of the world.With the development of modern agriculture,the demand on the film performance have become increasingly,thus,various functional films are developed.Light conversion agent is a kind of new functional additives which should be developed for the need of modern high efficiency and high quality agriculture.At present,there are many kinds of light conversion agents that can match the absorption of light energy by chloroplast,but there are many disadvantages such as low light intensity,poor compatibility with resin.In order to get a good performance,higher conversion eff-iciency and better compatibility with resin,the Ba3MgSi2O8 Eu2+,Mn2+ rare earth doped light conversion agent is synthesized in this dissertation,and applied to a polyethylene(PE)resin.The light conversion agent is synthesized by high temperature solid state reaction under a reducing atmosphere.The luminescent properties of light conversion agent are systematic researched on the Eu2+ and Mn2+ doping concentration,calcination temperature,and calcination time.The results showed that the Ba3MgSi2O8:Eu2+,Mn2+ with a strong blue light had the high crystallinity when the doping amount of Eu2+ was 8%,the doping amount of Mn2+ was 10%,calcination temperature was 1300?,and the roasting time was 3.5h.And the emission peak located at 436 nm.The excitation spectrum of the sample showed that a broadband excitation peak appeared from 600 nm to 680 nm with high intensity in the orange region.The Ba3MgSi2O8:Eu2+,Mn2+rare earth light conversion agent was modified by using the nano silica and silane coupling agents.The optimized surface modificated condition was obtained by the orthogonal experiment studied on the effect of coating time,temperature and mass fraction of silane coupling agent.The sample was characterized by scanning electron microscopy(SEM)and fluorescence spectrometer.The results showed that the maximum emission intensity emerged when the coating time was 3h,coating temperature was 90?,and the mass fraction of silane coupling agent was 2%.Through the analysis of SEM,a compact homogeneous film was coated on the surface of the rare earth light conversion agent.The excitation and emission spectrum are not influenced by the film,only the intensity slightly decreases.In addition,the compatibility of the modified light conversion agent with resin was enhanced,and the macro mechanical properties of the film were improved.