Research on space charge distribution in composite of Low Density Polyethylene and Nano Silver

Double-solution mixture method was employed in the preparation of the composite of low density polyethylene/Nano-silver. Space charge distributions in samples with different nano-silver concentrations were measured using the pulsed electro-acoustic (PEA) method. In the experiment, samples were tested under three different levels of electrical stress, respectively: 10kV/mm, 30kV/mm and 50kV/mm. Discharge characteristics of the samples were examined as well. Test results show that the involvement of nano-silver in LDPE causes larger space charge accumulation on the surface of composite samples than pure LDPE sample does. Within the extent of concentrations studied in this paper, it is interesting that concentrations of nano-silver up to 0.04%wt can further enhance interface charge, while lower ones can not. Meanwhile, characteristics of bulk charge in composites are impacted by the introduction of nano-silver. According to the data of the discharge experiment, it is found that the sample with a nano-silver ratio of 0.02%wt has a larger amount of heterocharge near cathode than the sample with a nano-silver ratio of 0.01%wt does. Additionally, samples filled with nano-silver retain about twice more bulk charge than pure LDPE samples, which shows that nano-silver can enhance the depth of traps in composites.