Abstract: The Sr2MgSi2O7∶ Eu2+,Dy3+ nanometer luminescent materials were prepared by hydrothermal coprecipitation method and surface modification was carried out.The effects of different metal complexing agents on the particle size,dispersibility and luminescent properties of the samples and the properties of the samples after surface modification were studied.The effects of different metal complexing agents on the crystal properties and luminescent properties of Sr2MgSi2O7∶Eu2+,Dy3+ were studied by X-ray diffraction,excitation emission and afterglow properties.The effects of different metal complexing agents on the particle size and dispersibility of the particles were studied by SEM and TEM.The results show that the crystallization and luminescent properties of samples with adding EDTA are good and the particle size is 50-200 nm,which is the best additive for preparing Sr2MgSi2O7∶ Eu2+,Dy3+ nano-luminescent particles.In addition,after the surface modification of the sample,the connection of the functional group and the potential of the functional group were studied by infrared spectroscopy and Zeta potential analysis,The particle size distribution,morphology and core-shell structure of the surface modified samples were studied by nano-particle size analysis,SEM and TEM.The results show that the SiO2 shell is successfully coated on the surface of the sample,and the suspension performance of the long afterglow nanoparticles after SiO2 coating is proved by the suspension test.

Key words: The Sr2MgSi2O7∶ Eu2+,Dy3+ nanometer luminescent materials were prepared by hydrothermal coprecipitation method and surface modification was carried out.The effects of different metal complexing agents on the particle size,dispersibility and luminescent properties of the samples and the properties of the samples after surface modification were studied.The effects of different metal complexing agents on the crystal properties and luminescent properties of Sr2MgSi2O7∶Eu2+,Dy3+ were studied by X-ray diffraction,excitation emission and afterglow properties.The effects of different metal complexing agents on the particle size and dispersibility of the particles were studied by SEM and TEM.The results show that the crystallization and luminescent properties of samples with adding EDTA are good and the particle size is 50-200 nm,which is the best additive for preparing Sr2MgSi2O7∶ Eu2+,Dy3+ nano-luminescent particles.In addition,after the surface modification of the sample,the connection of the functional group and the potential of the functional group were studied by infrared spectroscopy and Zeta potential analysis,The particle size distribution,morphology and core-shell structure of the surface modified samples were studied by nano-particle size analysis,SEM and TEM.The results show that the SiO2 shell is successfully coated on the surface of the sample,and the suspension performance of the long afterglow nanoparticles after SiO2 coating is proved by the suspension test.