Silver tree

In this paper, AgNO/sub 3/ (silver nitrate) solution was used as liquid electrode to accelerate the growth of water trees in polyethylene. It was found that water trees grown in AgNO/sub 3/ solution can be colored spontaneously during their formation, their areas are brownish-yellow, and they grow fast. Scanning electron microscopy (SEM) revealed microchannels in the AgNO/sub 3/-grown water tree with diameters from 0.2 to 0.5 /spl mu/m. In fact, these microchannels are possibly filled with metallic silver reduced from silver ions, and these water trees are referred to as 'silver trees'. The structure of the silver trees is studied and analyzed in comparison with sulfide trees and blue water trees. The effects of silver ions (Ag/sup +/) in the silver tree region are investigated and a comparison is made with other ions such as K/sup +/, Na/sup +/, Mg/sup ++/, and Cu/sup ++/ in water trees. The trees from AgNO/sub 3/ solution grow much faster than trees from the other solutions. Finally, the mechanism of the formation of silver trees is suggested.