Controllable preparation of CaCu3Ti4O12 nanowires and its strengthening effect on high dielectric polymer composites.

CaCu₃Ti₄O₁₂ nanowires (CCTO-NWs) with different aspect ratios were synthesized by two-step hydrothermal method. CCTO-NWs/PVDF composites were prepared using CCTO-NWs as filler and polyvinylidene fluoride (PVDF) as matrix. The effects of CCTO-NWs content and its aspect ratio on dielectric properties of composites were investigated. Results showed that aspect ratios of CCTO-NWs were obtained as 11.84, 14.47, 17.11, and 19.74 by controlling the first hydrothermal reaction temperature to be 180 °C, 200 °C, 220 °C, and 240 °C. At 10² Hz, the dielectric constant of 70-wt% CCTO-NWs/PVDF composite can reach 62.94, which is 3.7 times higher than that of 10-wt% CCTO-NWs/PVDF composite (13.47). Adding CCTO-NWs with high aspect ratio into matrix can effectively improve dielectric constant. When CCTO-NWs content is 60-wt%, compared with fillers with an aspect ratio of 11.84, fillers with an aspect ratio of 19.74 can make the dielectric constant of composites increase about 64%. [ABSTRACT FROM AUTHOR]