The creep and recovery behaviors are of great importance for the electrorheological elastomers (EREs), while it is lack of relevant research in previous reports. In this work, the creep and recovery properties of silane coupling agent modified-TiO2 particles based EREs were systematically investigated, and the influence of particle content, electric field strength and temperature on creep and recovery behaviors were analyzed. The results indicate the creep and recovery behaviors of the EREs are affected by particle volume fraction and temperature obviously. The creep resistance of EREs are enhanced with the ascending electric field strength, and the blocking effect of particles on polymer chain segments is further clarified by fitting the creep data with Findley and Burgers model. The creep compliance curves of the EREs under various temperatures and electric field intensities were compared, and the curves were shifted along time axis to get a master compliance curve at a reference electric field strength according to the proposed time-electric field superposition principle (TESP). It is shown that TESP could provide an accelerated measuring technique for evaluating the long-term viscoelastic properties of EREs.
When in an alternating magnetic field, magneto-thermal sensitive hydrogels can absorb solvent molecules, causing the gel network to swell several times to its original size. By conducting experiments with magnetic PNIPAm hydrogels (M-PNIPAm), the parameters of the theoretical model for magneto-thermal sensitive hydrogels were experimentally determined. Subsequently, the mechanical behavior of M-PNIPAm hydrogel was studied through finite element analysis and tensile experiments. The numerical calculations based on the thermodynamic model with specific parameters showed consistency with experimental results. The comparison indicated that the proposed theory for magneto-thermal sensitive hydrogels can accurately predict the mechanical property of M-PNIPAm hydrogel, providing theoretical support for investigating large deformation of magneto-thermal sensitive hydrogels. Furthermore, we discovered that the variation of magnetic particle content significantly influence the mechanics properties of hydrogel. Our findings provide valuable insights for the research and application of magneto-thermal sensitive hydrogels.
危险品化学品经营许可证（带存储）