Assembly And Electric Field Response Properties Of Polymer/barium Titanate Nanoparticles With Core-shell Structure

In the excellent electrorheological materials, BaTiO₃ particles with high dielectric constant, low dielectric loss and good stability are regarded as the most promising electrorheological materials. But the shortcomings of high density and poor dispersion affect its electric field response performance. In order to overcome the poor dispersion stability of BaTiO₃ particle and keep its high electric field response performance. In this paper, BaTiO₃ nanoparticle was assembled on the surface of polymer microspheres to obtain core-shell structure composite nanoparticles and the electric field response performance of composite particles were studied.In this study, we prepared the nanoscale polymer microspheres, such as Gelatin、 Chitosan and Polystyrene. BaTiO₃ with an average particle size about 50 nm was assembled on the surface of polymer microspheres to prepare three kinds of composite particles with different core material and the conditions of preparing polymer microspheres were discussed in detail, particles’ morphology, structure, composition and content have been studied by measuring instrument. On this base, composite particles were dispersed into gelatin hydrosol system cured with/without an electric field to obtain electrorheological elastomer, by analyzing the difference of storage modulus to study the electric response of composite particles.1. Nano BaTiO₃ particles were prepared by the solvent thermal method, and the polymer microspheres with uniform particle size were prepared by microemulsion method. Under certain conditions, three kinds of polymer/BaTiO₃ composite particles with different core material were prepared by self-assembly method, the morphology, composition and structure of the composite particles were studied. The results showed that the polymer microspheres as the core material with an average particle size about 600 nm, the thickness of cubic BaTiO₃ shell is about 50 nm and cubic BaTiO₃ shell accounts for about 50% of the total weight. Besides, the core and the shell materials are combined by chemical processes and the composite particles still has good hydrophilic ability.2. Composite particles were dispersed into gelatin hydrosol system cured with/without an electric field gelling to obtain two kinds of electrorheological elastomer. Dynamic viscoelastic spectrum analyzer was used to measure the storage modulus of elastomers with three kinds of composite particles to study the electric response of particles.The results showed that the storage modulus of composite particles has increased significantly under electric field, indicating that the composite particles had a good response to the electric field and has large improvement compared with the bare BaTiO₃, indicating that BaTiO₃ was assembled on the surface of polymer microspheres to prepare polymer/BaTiO₃ composite particles can overcome the shortcomings of easy sedimentation of BaTiO₃ and improve the dispersion stability obviously, thereby improving the electric field response performance of BaTiO₃ particles.