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Preparation Of Two Kinds Of Zinc Borate Micro / Nanomaterials And Their Flame Retardancy And Luminescent Properties

Posted on:2016-11-26Degree:MasterType:Thesis
Country:ChinaCandidate:L J QiaoFull Text:PDF
GTID:2271330473462274Subject:Inorganic Chemistry
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Zinc borate is a traditional flame retardants, widely used in plastics, rubber, and paint, etc. However, the zinc borate particles are hardly dispersed in the matrix, which restrains their users. At present, the zinc borate host luminescent materials have made certain progress. However, it was mainly prepared by high temperature solid-state method, and the research about the relationships between the preparation method, condition and the morphology, and luminescence properties of products are still need to be further studied.In this work, we takes rare-earth doping zinc borate host luminescents as the research object, two kinds of the zinc borate Zn[B3O3(OH)5]·H2O and Zn6O(OH)(BO3)3 nano-structures have been prepared. ZnB4O7 and ZnB2O4 were obtained by annealing of the as-prepared Zn[B3O3(OH)5]·H2O with the phase inversion method. The obtained samples were characterized by EDS, XRD, IR, and SEM. The luminescent properties were studied, and the flame retardant property of hydrated zinc borate were also studied. Details are as follows:(1) Zn[B3O3(OH)5]·H2O, Zn[B3O3(OH)5]·H2O:Eu3+ and Zn[B3O3(OH)5]·H2O: Eu3+, Tb3+ were prepared by one-step homogeneous precipitation method for the first time, and then the ZnB4O7:Eu3+ and ZnB2O4:Eu3+products were obtained by annealing of the as-prepared Zn[B3O3(OH)5]·H2O:Eu3+ at 600-700℃ and 800-900℃, respectively. At the same time, ZnB2O4:Eu3+,Tb3+ products were obtained by annealing of the as-prepared Zn[B3O3(OH)5]·H2O:Eu3+,Tb3+ at 900℃. Their phase, morphology and luminescent properties were also studied. The luminescent intensity reached a maximum when the doped concentration of Eu3+ was 6%. The luminescent intensity of ZnB2O4:Eu3+ increased with the rise of calcination temperature, and reached a maximum when the temperature was 900℃.The luminescent intensity increased at first and then decreased with the prolonging of calcination time, and reached a maximum when the calcination time was 6h. The ZnB2O4:Eu3+ phosphor obtained by the phase inversion method exhibits much stronger emission intensity. Also, ZnB2O4:Eu3+,Tb3+ phosphor obtained by the phase inversion method exhibits much stronger emission intensity and the ratio of R/O than that prepared by the conventional high temperature solid-state reaction method.(2) A low hydrated zinc borate Zn6O(OH)(BO3)3 and its Zn6O(OH)(BO3)3:Eu3+ phosphor with five kinds of morphologies have been firstly prepared by a hydrothermal method, which were characterized on the phase, morphology and luminescent properties. At the same time, we studied the effects of Eu3+ doping concentration, calcination temperature, calcination time, and the preparation methods on the luminous intensity. The luminescent intensity reached a maximum when the doped concentration of Eu3+ was 10%, which was a relatively high quenching concentration. And the strongest emission peak of Zn6O(OH)(BO3)3:Eu3+ was located at 613 nm (red). Its luminescent intensity increased at first and then decreased with the prolonging of time, and reached a maximum when the time was 10 h. The ball-like Zn6O(OH)(BO3)3:Eu3+ structure phosphor exhibits much stronger emission intensity than that prepared by the other morphology.(3) The flame retardant properties of the prepared hydrated zinc borate Zn[B3O3(OH)5]·H20 and Zn6O(OH)(BO3)3 nanostructures were investigated by the thermal analysis method and limited oxygen index method. The experiments show that the smaller size of nanostructure, the more uniform morphology and the more water of crystallization, the better flame retardant property of the sample.
Keywords/Search Tags:Zinc borate, Preparation, Nanostructure, Luminescent properties, Flame retardant property
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