... sizes are hundreds of nm - several µm, excellent solubility in water and DMF, etc, metallic content < 10ppm, not soluble impurities < 0. ... 4 layers, hundreds of nm - several µm, excellent solubility in water and DMF,etc. Metallic content <10ppm, not soluble impurities < 0. ... 8 layer, 2-4 nm thick , hundreds of nm-dozens of µ m in size, solid powder, > 99% purity, good electrical conductivity, excellent ...