Preparation of nanosized ZnO and dielectric properties of composites filled with nanosized ZnO

Nanosized ZnO powder is prepared by a precipitation method that is simple, convenient manipulation and low energy consumption. The process can produce white ZnO powder of 50-90 nm in size. The dielectric constants of composites with nanosized ZnO filler are also studied in detail in a frequency range of 1-10 MHz by an impedance analyzer. Composites with more ZnO filler have relatively large dielectric constants and losses and they increase with increasing the frequency. High frequency has a remarkable effect on dielectric constants and losses of the composites. Finally, the high dielectric constants and losses of the composites appear under 10 MHz in experimental study. In addition, mixing temperature and time also play an important role on dielectric constants and losses. High temperature and long time during the mixing process might induce the structure change of low-density polyethylene (LDPE). Therefore, the composites have a high dielectric constants and losses. (C) 2002 Elsevier Science B.V. All rights reserved.