Core-Shell Structured Polystyrene/BaTiO3 Hybrid Nanodielectrics Prepared by In Situ RAFT Polymerization: A Route to High Dielectric Constant and Low Loss Materials with Weak Frequency Dependence

• Published in: Macromolecular rapid communications. 2012-11, Vol.33 (22), p.1921-1926
• Main Authors: Yang, Ke, Huang, Xingyi, Xie, Liyuan, Wu, Chao, Jiang, Pingkai, Tanaka, Toshikatsu
• Format: Article
• Language: English
• Subjects: Applied sciences; Barium Compounds - chemistry; barium titanate (BaTiO3); core-shell structure; Dependence; dielectric materials; Dielectric properties; Exact sciences and technology; Nanocomposites; Nanocomposites - chemistry; Organic polymers; Physicochemistry of polymers; Polymerization; Polymers with particular structures; Polystyrenes - chemistry; Preparation, kinetics, thermodynamics, mechanism and catalysts; reversible addition-fragmentation chain transfer (RAFT); Surface Properties; Titanium - chemistry
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.201200361

A novel route to prepare core–shell structured nanocomposites with excellent dielectric performance is reported. This approach involves the grafting of polystyrene (PS) from the surface of BaTiO3 by an in situ RAFT polymerization. The core–shell structured PS/BaTiO3 nanocomposites not only show significantly increased dielectric constant and very low dielectric loss, but also have a weak frequency dependence of dielectric properties over a wide range of frequencies. In addition, the dielectric constant of the nanocomposites can also be easily tuned by varying the thickness of the PS shell. Our method is very promising for preparing high‐performance nanocomposites used in energy‐storage devices. In situ RAFT polymerization as a novel route to prepare PS@BaTiO3 core–shell structured nanocomposites with excellent dielectric performance is reported. The insulating PS shells are robustly anchored on the BaTiO3 surface to prevent the agglomeration of the nanoparticles, and also act as the polymer matrix. The PS@BaTiO3 nanocomposites exhibit high dielectric constants, low dielectric loss, and weak frequency dependence over a wide range of frequencies.