Ferroelectric Polymer Nanocomposites Research Articles

Tailoring Dielectric Properties and Energy Density of Ferroelectric Polymer Nanocomposites by High-k Nanowires.

High dielectric constant (k) polymer nanocomposites have shown great potential in dielectric and energy storage applications in the past few decades. The introduction of high-k nanomaterials into ferroelectric polymers has proven to be a promising strategy for the fabrication of high-k nanocomposites. One-dimensional large-aspect-ratio nanowires exhibit superiority in enhancing k values and energy density of polymer nanocomposites in comparison to their spherical counterparts. However, the impact of their intrinsic properties on the dielectric properties of polymer nanocomposites has been seldom investigated. Herein, four kinds of nanowires (Na2Ti3O7, TiO2, BaTiO3, and SrTiO3) with different inherent characteristics are elaborately selected to fabricate high-k ferroelectric polymer nanocomposites. Dopamine functionalization facilitates the excellent dispersion of these nanowires in the ferroelectric polymer matrix because of the strong polymer/nanowire interfacial adhesion. A thorough comparative study on the dielectric properties and energy storage capability of the nanowires-based nanocomposites has been presented. The results reveal that, among the four types of nanowires, BaTiO3 NWs show the best potential in improving the energy storage capability of the proposed nanocomposites, resulting from the most signficant increase of k while retaining the rather low dielectric loss and leakage current.

Ferroelectric polymer nanocomposites for room-temperature electrocaloric refrigeration.

Solution-processable ferroelectric polymer nanocomposites are developed as a new form of electrocaloric materials that can be effectively operated under both modest and high electric fields at ambient temperature. By integrating the complementary properties of the constituents, the nanocomposites exhibit state-of-the-art cooling energy densities. Greatly improved thermal conductivity also yields superior cooling power densities validated by finite volume simulations.

Solution-processed ferroelectric terpolymer nanocomposites with high breakdown strength and energy density utilizing boron nitride nanosheets

Ferroelectric polymer nanocomposites with boron nitride nanosheets exhibit greatly improved energy densities and higher charge–discharge efficiencies.

Energy storage in ferroelectric polymer nanocomposites filled with core-shell structured polymer@BaTiO3 nanoparticles: understanding the role of polymer shells in the interfacial regions.

The interfacial region plays a critical role in determining the electrical properties and energy storage density of dielectric polymer nanocomposites. However, we still know a little about the effects of electrical properties of the interfacial regions on the electrical properties and energy storage of dielectric polymer nanocomposites. In this work, three types of core-shell structured polymer@BaTiO3 nanoparticles with polymer shells having different electrical properties were used as fillers to prepare ferroelectric polymer nanocomposites. All the polymer@BaTiO3 nanoparticles were prepared by surface-initiated reversible-addition-fragmentation chain transfer (RAFT) polymerization, and the polymer shells were controlled to have the same thickness. The morphology, crystal structure, frequency-dependent dielectric properties, breakdown strength, leakage currents, energy storage capability, and energy storage efficiency of the polymer nanocomposites were investigated. On the other hand, the pure polymers having the same molecular structure as the shells of polymer@BaTiO3 nanoparticles were also prepared by RAFT polymerization, and their electrical properties were provided. Our results show that, to achieve nanocomposites with high discharged energy density, the core-shell nanoparticle filler should simultaneously have high dielectric constant and low electrical conductivity. On the other hand, the breakdown strength of the polymer@BaTiO3-based nanocomposites is highly affected by the electrical properties of the polymer shells. It is believed that the electrical conductivity of the polymer shells should be as low as possible to achieve nanocomposites with high breakdown strength.

Energy Storage: High Energy and Power Density Capacitors from Solution‐Processed Ternary Ferroelectric Polymer Nanocomposites (Adv. Mater. 36/2014)

Energy Storage: High Energy and Power Density Capacitors from Solution‐Processed Ternary Ferroelectric Polymer Nanocomposites (Adv. Mater. 36/2014)

High energy and power density capacitors from solution-processed ternary ferroelectric polymer nanocomposites.

Concurrent improvements in dielectric constant and breakdown strength are attained in a solution-processed ternary ferroelectric polymer nanocomposite incorporated with two-dimensional boron nitride nanosheets and zero-dimensional barium titanate nanoparticles that synergistically interact to enable a remarkable energy-storage capability, including large discharged energy density, high charge-discharge efficiency, and great power density.

Enhancement of breakdown strength and energy density in BaTiO3/ferroelectric polymer nanocomposites via processing-induced matrix crystallinity and uniformity

Blade casting of BaTiO3/P(VDF-co-HFP) nanocomposites has improved morphology resulting in enhanced breakdown strength and energy density (7 J cm−3).

Ferroelectric polymer/silver nanocomposites with high dielectric constant and high thermal conductivity

Ferroelectric polymer nanocomposites with silver (Ag) nanoparticles as inclusions were prepared and the dielectric properties and thermal conductivity were studied. The results showed that the nanocomposites have high dielectric constant and high thermal conductivity. When the loading level of Ag nanoparticles is 20.0 vol %, the dielectric constant and thermal conductivity of the nanocomposites were 120 at 103 Hz and 6.5 W/mK, respectively. Our results also showed that there is no percolation in the nanocomposites when Ag loading range is within 20.0%.