Influences of process conditions on microstructure and dielectric properties of ceramic-polymer composites are systematically studied using CaCu3Ti4O12 (CCTO) as filler and P(VDF-TrFE) 55/45 mol.% copolymer as the matrix by combining solution-cast and hot-pressing processes. It is found that the dielectric constant of the composites can be significantly enhanced–up to about 10 times – by using proper processing conditions. The dielectric constant of the composites can reach more than 1,000 over a wide temperature range with a low loss (tan δ ~ 10−1). It is concluded that besides the dense structure of composites, the uniform distribution of the CCTO particles in the matrix plays a key role on the dielectric enhancement. Due to the influence of the CCTO on the microstructure of the polymer matrix, the composites exhibit a weaker temperature dependence of the dielectric constant than the polymer matrix. Based on the results, it is also found that the loss of the composites at low temperatures, including room temperature, is determined by the real dielectric relaxation processes including the relaxation process induced by the mixing.

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We report here a clinical case of phaeohyphomycosis in an 18-year-old male giant panda (Ailuropoda melanoleuca). Skin lesions on the giant panda disappeared following 2 months of treatment with ketoconazole. Three months after discontinuing the treatment, there was a clinical and mycological relapse. The disease progression was no longer responsive to ketoconazole. Microscopy and polymerase chain reaction (PCR) analysis revealed that the infection was caused by Cladosporium cladosporioides. A 4-month treatment regime with Itraconazole oral solution (700 mg per day) successfully terminated the infection.

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The flexible and free‐standing nanocomposite films were fabricated by a simple solution‐casting process using BaTiO3 nanoparticles as fillers and P(VDF‐CTFE) 91/9 mol% as polymer matrix. To obtain good wettability between ceramic and polymer, the coupling agent 3‐Aminopropyltriethoxysilane was used to modify the surface of BaTiO3 fillers. A good compatibility of BaTiO3 and P(VDF‐CTFE) was achieved when a small amount of coupling agent was used for the surface modification of BaTiO3 fillers; therefore, the nanocomposites with a dense and uniform microstructure was obtained. It was experimentally found that both dielectric constant and breakdown strength were increased with a suitable amount of coupling agent due to the good compatibility. A dielectric constant of 51 at 1 kHz was obtained with 30 vol% fillers and 2 wt% coupling agent, which was about four times of that for the pure P(VDF‐CTFE) film. When an appropriate amount of coupling agent was coated on fillers, the energy storage density of the composite system was improved. A maximal discharge energy‐storage density of 3.8 J/cm3 was obtained for the nanocomposite film with 5 vol% of BaTiO3 and 2 wt% coupling agent, which is much higher than that of the composites without coupling agent.

The influence of a commercial coupling agent on the dielectric properties and microstructure of ceramic-polymer nanocomposites are studied. Free-standing BaTiO3-P(VDF-CTFE) films were fabricated using a simple solution-casting process, and the good wettability between fillers and polymer matrix was obtained by using 3-Aminopropyltriethoxysilane as coupling agent. It is found that the coating of a small amount of coupling agent on the surface of BaTiO3 fillers results in an enhanced dielectric constant, a higher breakdown strength and a larger energy-storage efficiency. When an excessive amount of coupling agent was used, the non-attached coupling agent molecules participated in the complex reactions and result in the aggregation of fillers and the reduction of dielectric constant. It is also found that the surface modification of fillers has a complicated influence on its dielectric behavior which leads to an increase in the dielectric loss of the nanocomposites. When an appropriate amount of coupling agent is coated on fillers, the energy storage density of the nanocomposite is improved due to the enhanced dielectric constant and higher breakdown strength. A maximal discharged energy-storage density of about 4.0 J cm−3 was obtained from the nanocomposite film containing 15 vol% of surface modified BaTiO3 fillers with 1 wt% of KH550, which is about 3 times of that for the nanocomposite without coupling agent.

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