The mixture was filtered and washed with 1:10 HCl
solution (5 L) in order to remove metal ions
The GO product
was suspended in distilled water to give a viscous, brown, 2%
dispersion, which was subjected to dialysis to completely
remove metal ions and acids.
The resulting 0.5% w/v GO
dispersion, which is stable for a period of years, was used to
prepare exfoliated GO
Exfoliation was achieved by dilution of the 0.5% GO dispersion
(1 mL) with deionized water (24 mL), followed by 15 min
sonication. The resulting homogeneous yellow-brown sol,
which contained 0.2 g/L GO, was stable for a period of months
and was used for film preparation.