Preparation Of Pr³⁺ Doped NaNbO₃ Mechanoluminescent Materials And Its Anti-counterfeiting Application Research

It is of great significance to develop new mechanoluminescent materials to meet the demand of modern anti-counterfeiting field.Mechanoluminescent materials can transform the mechanical stimulation into photon emission,which provides a new possibility for the development of new anti-counterfeiting methods.However,some problems seriously hinder the research and application of mechanoluminescence(ML).The first is that the mechanisms of ML are not well understood,which has a great impact on the development of materials and the improvement of its properties.Secondly,there are few reports on the preparation of mechanoluminescent nanomaterials,which hinders the application prospect of ML.The third is that the ML application prospect is broad,but the actual development and application is limited.Focusing on these three problems,this paper obtained nanomaterials with uniform morphology through ingenious design of material preparation path.The photoluminescence(PL),mechanoluminescence and thermoluminescence(Th L)properties of the synthetic materials were studied systematically,and the mechanism of ML was discussed.Finally,two kinds of anti-counterfeiting applications about ML are designed.The research results are summarized as follows:The strategy of preparing Pr3+ doped NaNbO3 nanomaterials by hydrothermal and annealing two-step method is designed.And through the annealing temperature adjustment,the effects of temperature on the crystal structure,morphology,PL and ML properties of the materials were systematically studied.The results show that after annealing at 1100 oC for 4 h,the size of the material is 150 nm,and the PL and ML are the strongest.The Th L spectrum shows that there is a relationship between the ML mechanism and the number of electronic.After the synthesis temperature of nanomaterials was determined,the ML intensity was optimized by adjusting the doping amount of Pr3+ in NaNbO3 host materials.The effects of the doping amount of Pr3+ on the crystal structure,morphology,PL and ML properties of the materials were systematically studied.The results show that the ML intensity of the material is the strongest when the doping amount of Pr3+ is 0.750%.It has excellent performance of high brightness and recoverability,and the ML intensity of the material is proportional to the applied force.According to the above data analysis,the mechanism of ML of the materials was expounded by using the piezoelectricity-induced ML model.Based on the above two materials,the ML pattern anti-counterfeiting and the electronic signature ML anti-counterfeiting application research are designed respectively.The results show that the anti-counterfeiting level of ML pattern can be greatly improved.The electronic signature ML anti-counterfeiting method can not only record the static information of the signer,but also record the dynamic information generated by the signer,including the signature speed and signature pressure.This greatly improves the anti-counterfeiting ability of electronic signature.