High-resolution study of water trees grown in silver nitrate solution

Water trees were grown in polyethylene submerged in a silver nitrate solution. Treed regions were then examined with optical microscopy, scanning electron microscopy, transmission electron microscopy (TEM) and energy dispersive spectroscopy. These water trees provided the basis for improved TEM resolution due to the formation of electron dense silver-rich particles in the treed region. The results show water trees to be composed of individual and discrete entities and do not support the theory of interconnecting channels. The possible presence of interconnecting 'chemical' pathways can not be ruled out. The decomposition of the silver nitrate to metallic silver particles suggests the necessity for increased electron density in the treed region.