Study on the effects of CNFs doping concentration on space charge of CNFs/LDPE nanocomposites

In order to improve the performance of the low density polyethylene,the nickel plated carbon nanofibers(CNFs) were added into low density polyethylene(LDPE) by melt blending techniques,then to make CNFs/LDPE double-layer samples by semi-conducting layer and insulating layer.The pulsed electroacoustic(PEA) method can be used to measure the space charge distribution.The experimental results showed that when the CNFs content was below 1%(wt.),CNFs/LDPE semi-conducting layer to the weakening of the electric field effect was relatively small,then samples had more residual space charge with the increase of direct current(DC) electric field.If the CNFs content was more than 1%(wt.),the conductive mechanism of the CNFs/LDPE semi-conducting layer had been changed,the injection of space charge quantity rarely and after short circuit there will be almost no residual.Especially when the CNFs content was 5%,Only near the cathode there have trace charge interior of the sample almost no space charge distribution.