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

Nanosized ZnO powder was prepared by the precipitation method which can produce white ZnO powder 50nmsimilar to90nm. The dielectric constants of composites with nanosized ZnO fillers were also studied in detail in a frequency range of 1MHz-10MHz by LF impedence analyzer. The results show that the composites with more nanosized ZnO fillers were relatively large dielectric constants and losses and they increase with increasing the measurement frequencies. High frequency has a remark effect on dielectric constants and losses of the composites because ZnO is a polar molecule and it will be polarized under alternative current field. The polarization is quick and consumes a great deal of energy. The high dielectric constants and losses of the composites appear under 10 MHz in experimental study. In addition, mixture temperature and time have also an important influence on dielectric constants and losses. High temperature and long time will induce the decomposition and oxygenation of LDPE matrix and form some polar molecular. These conditions can also produce the different interfaces between the LDPE matrix and ZnO fillers. All of factors can play an important role in effecting on the dielectric constant and loss of composites.