Strawberry‐like Core–Shell Ag@Polydopamine@BaTiO₃ Hybrid Nanoparticles for High‐k Polymer Nanocomposites with High Energy Density and Low Dielectric Loss

Abstract

high-energy-density storage devices, and electromechanical actuators. [1][2][3][4][5][6] In general, the traditional ferroelectric ceramics such as BaTiO 3 (BT) have large dielectric constant, but the low breakdown strength and poor processing property limit their application. On the other hand, despite having the merits of high breakdown strength, low dielectric loss and ease of processing, the polymer fi lms generally suffer from low dielectric constant (e.g., <5), which seriously limit their application in the next generation of energy storage devices. [ 7 ] Introducing high-dielectric-constant (high-k ) ceramics into polymer matrix is a classic approach to high-k composite materials and has been extensively investigated in the past decades. [8][9][10][11][12][13][14] However, the large electrical mismatch between ceramic fi llers and polymers usually results in signifi cant decrease of breakdown strength. In addition, the poor compatibility between the inorganic fi llers and the organic polymer matrix results in weak interfacial adhesion and aggregation, leads to high dielectric loss and further decrease of breakdown strength. [ 15,16 ] To solve these issues, a variety of novel nanostructured inorganic-organic hybrid fi llers (e.g., core-shell structured nanoparticles) have been developed. In such materials, the inorganic core processes high dielectric constant, and the organic shell generally provides strong interchain forces with polymer matrix [17][18][19][20] or directly acts as matrix. [21][22][23][24][25][26][27][28][29] Therefore, the interfacial adhesion between the inorganic fi llers and the organic polymer matrix can be improved and the dielectric properties of the resulting nanocomposites can be greatly enhanced. For example, via in situ metallocene catalytic olefi n polymerization, a series of core-shell structured polyolefi n-based nanocomposites with high dielectric constant and low dielectric loss were prepared by Marks and co-workers. [23][24][25][26][27] Through in situ atom transfer radical polymerization (ATRP) [ 22 ] and reversible addition-fragmentation chain transfer (RAFT) [ 20,21 ] polymerization from the BaTiO 3 surface, our group also successfully prepared a series of core-shell structured nanocomposites with excellent dielectric properties. Thus, more and more attention has been paid to the development of new materials with the aforementioned nanostructured to realize the desirable dielectric properties in Flexible nanocomposites comprising of polymer and high-dielectric-constant (high-k ) ceramic nanoparticles are becoming increasingly attractive for dielectric and energy storage applications in modern electronic and electric industry. However, a huge challenge still remains. Namely, the increase of dielectric constant usually at the cost of signifi cant decrease of breakdown strength of the nanocomposites because of the electric fi eld distortion and concentration induced by the high-k fi ller. To address this long-standing problem, by using nano-Ag decorated core-shell polydopami...

Enhanced Thermal Conductivity and Dielectric Properties of Iron Oxide/Polyethylene Nanocomposites Induced by a Magnetic Field

“…The oriented distribution of the Fe 3 O 4 clusters is beneficial for the formation of a conductive network in this direction, which can be regarded as a great amount of parallel-connected micro-capacitors, resulting in a greatly enhanced dielectric constant 39, 40 . It should be noted that the dielectric properties in our present study is even higher than those of many previous reports 21, 23, 41–43 . For example, as shown in Table 3, the obtained dielectric constant is higher than that of BZT-BCT/PVDF composites containing 24 vol.% BZT-BCT ( ɛ  = 37.2 at 10 Hz) 41 .…”

Versatile Surface Modification Using Polydopamine and Related Polycatecholamines: Chemistry, Structure, and Applications

“…Template directed synthesis has been used to make hollow magnetite nanoparticle impregnated polydopamine microspheres and hollow silver nanoparticle decorated n‐doped carbon microspheres when the polymer templates were removed using solvent and calcination, respectively. Using similar methods, polycatecholamines have been used extensively as an intermediate layer in the formation of core–shell nanoparticles . These core–shell nanoparticles often have multiple functional layers such as magnetite nanoparticles coated with polydopamine for the subsequent deposition of metallic nanoparticles generating magnetically separable, reusable catalysts .…”

Tailoring the irreversible thermal expansion of 1,3,5‐triamino‐2,4,6‐trinitrobenzene crystals by bioinspired polydopamine coating

“…It is well known that as a biological neurotransmitter, dopamine is a biomaterial of considerable interest for a variety of applications, due to the mild reaction conditions and applicability to various materials . Inspired by the strong chemical adhesion of mussels, the self‐polymerization of dopamine in a weak alkaline aqueous solution provides a facile and versatile method for coating various materials, such as glass, metal, polymer, and nanocarbon materials . Besides, polydopamine (PDA) is a crosslinked polymer with abundant benzene rings in the main chain.…”

“…21,22 Inspired by the strong chemical adhesion of mussels, the self-polymerization of dopamine in a weak alkaline aqueous solution provides a facile and versatile method for coating various materials, such as glass, metal, polymer, and nanocarbon materials. [22][23][24][25] Besides, polydopamine (PDA) is a crosslinked polymer with abundant benzene rings in the main chain. Hereby, PDA could simultaneously provide strong chemical adhesion and high rigidity and is favorable to coat the TATB crystals in order to reduce irreversible expansion.…”