Fig. 7
From: Double-layer PAA with different pore sizes and its growth kinetics based on anodizing current curves
Four-step anodizing corresponding current-time curves, (a) first anodization at 40 V in 3wt% oxalic acid, (b) second anodization at 28 V in 10wt% ammonium phosphite, (c) third anodization at 29 V in 10wt% ammonium phosphite, (d) forth anodization at 40 V in 3wt% oxalic acid.
