Reasearch On Interface Design And Mechanoluminescence Properties Of ZnS:Mn²⁺-based Composite Elastic Materials

ZnS:Mn²⁺-based composite elastic materials exhibit excellent mechanoluminescence properties under different stress stimulation,which have a broad application in lighting display,wearable fabrics,intelligent electronic skin and other fields.The optimization of its mechanoluminescence property is a hot issue for researchers.However,most of the current research only focus on optimizing the intrinsic mechanoluminescence properties of ZnS:Mn²⁺,ignoring the influence of the interfacial interactions between the composite elastomers and powder on mechanoluminescence.In this thesis,the interfacial interaction of ZnS:Mn²⁺-based composite elastic materials is regulated from two aspects,the matrix and powder,and the influence of the interfacial interaction on the mechanoluminescence properties of the composite elastic materials is further explored.It not only expands the application of ZnS:Mn²⁺mechanoluminescence materials,but also provides a new perspective for the performance optimization for mechanoluminescence materials.The detailed research contents are as follows:1.ZnS:Mn²⁺powder was prepared by high temperature solid phase method,and the interfacial interaction was designed by matrix effect.Based on the characteristics of polyurethane(PU)with elasticity,high transparency,internal multipolar groups and interfacial interaction between PU and powder,the conventional elastomer PDMS composited with ZnS:Mn²⁺was expanded to PU.It was confirmed that there was an interfacial interaction between ZnS:Mn²⁺and PU by characterization of scanning electron microscopy,mechanical properties and infrared spectroscopy testing.Then,the mechanoluminescence and thermoluminescence curves of ZnS:Mn²⁺/PU composite elastic materials were characterized to study the effect of interfacial interaction on the mechanoluminescence properties and mechanism.The results show that the mechanoluminescence intensity of ZnS:Mn²⁺/PU composite elastomer is about 40%higher than that of ZnS:Mn²⁺/PDMS,as well as can be maintained after tensile several cycles.2.Because of the high elasticity,good durability and wide application of ZnS:Mn²⁺/PDMS composite elastic materials,optimizing its mechanoluminescence performance has a great significance.In this part,the interface interaction of ZnS:Mn²⁺/PDMS composite elastic materials was optimized from the size of powder and surface modification.ZnS:Mn²⁺powder with uniform morphology of small particle size and mechanoluminescence properties was obtained by hydrothermal-treatment method,the heat treatment temperature,heat treatment time and Mn²⁺doping concentration variables.Moreover,the characterization of structure,morphology,photoluminescence and mechanoluminescence were carried out to obtain the best sample.Then the infrared spectra and contact angle tests were used to verify that oleic acid(OA)was successfully modified on the surface of ZnS:Mn²⁺powder,and the interfacial interaction between ZnS:Mn²⁺@OA and PU matrix was improved.The effect of interfacial interaction on the mechanoluminescence performance of ZnS:Mn²⁺@OA/PDMS composite elastic material were further studied by scanning electron microscopy,mechanical properties and mechanoluminescence test.The results show that under the premise of having the mechanoluminescence properties,the dispersibility of the ZnS:Mn²⁺@OA powder in the ZnS:Mn²⁺@OA/PDMS composite elastic materials is significantly improved compared with the commercial ZnS:Mn²⁺powder,which effectively improved the luminescence display resolution.At the same time,the flexibility and deformation capacity of the elastic materials are increased.