Core–Shell Structured BaTiO₃@Polyethylene in Low-Density Polyethylene: Modulation of Dispersion Structure and Improvement of Dielectric Properties

Organically modified dielectric filler nanoparticles with core–shell structures have received widespread attention when designing composites with excellent dielectric properties. Herein, the core–shell structured BaTiO₃@polyethylene (BT@PE) nanoparticles were prepared and the models of BT@PE filled low-density polyethylene (LDPE) composites were constructed. The interaction modulated nanoparticle dispersion structure and the effect of the core–shell structured BT@PE on the polarization and breakdown of the composites were studied by molecular dynamics (MD) simulations and finite element analysis (FEA). The results show that BT@PE modulated the interactions between particles, formed a well-dispersed structure in the LDPE matrix, and optimized the electric field distribution inside the composites. Moreover, due to the existence of microscopic transition layer, the core–shell structured BT@PE increased the interfacial polarization while suppressed the electric field distortion. BT@PE nanoparticles simultaneously enhanced the dielectric constant and breakdown strength of the composites.