Polymer composites containing hybrid particles with an organic carbonaceous shell coating on Ag cores were prepared by low‐cost solution processing. A stable high dielectric constant κ and low dielectric loss tan δ (see figure) were observed because of percolating interparticle barrier layers provided by the core/shell particles.

Manipulating microstructures of composites in three dimensions has been a long standing challenge. An approach is proposed and demonstrated to fabricate artificial nanocomposites by controlling the 3D distribution and orientation of oxide nanoparticles in a polymer matrix. In addition to possessing much enhanced mechanical properties, these nanocomposites can sustain extremely high voltages up to ≈10 kV, exhibiting high dielectric breakdown strength and low leakage current. These nanocomposites show great promise in resolving the paradox between dielectric constant and breakdown strength, leading to ultrahigh electrical energy density (over 2000% higher than that of the bench-mark polymer dielectrics) and discharge efficiency. This approach opens up a new avenue for the design and modulation of nanocomposites. It is adaptable to the roll-to-roll fabrication process and could be employed as a general technique for the mass production of composites with intricate nanostructures, which is otherwise not possible using conventional polymer processing techniques.

We prepared TiO 2 -rich CaCu 3 Ti 4 O 12 ͑CCTO͒ ceramics by a solid-state sintering process and observed large nonlinear electrical and high dielectric behaviors. Microstructure and phase composition analyses show that CCTO grain-amorphous/TiO 2 nanograin boundary-CCTO grain junction structures exist in these TiO 2 -rich CCTO ceramics, which leads to the nonlinear electrical and high dielectric properties. The temperature dependence of impedance spectroscopy and relationships between electrical current density versus applied electrical field indicate that the activation energy of the grain boundary for the TiO 2 -rich CCTO ceramics is almost the same as the potential barrier height and both of them are weakly independent of the doped concentration of TiO 2 , which supports the internal barrier layer capacitor model of Schottky barriers at the grain boundaries between semiconducting CCTO grains.

A concise construction of polycyclic quinolines via intramolecular [2 + 2 + 2] annulation of ω-cyano-1-alkynes with diaryliodonium salts was realized. The process produced polycyclic quinolines in high yields with readily available staring materials and was tolerated with halogen substituents.