Electrochemical and ellipsometric study of polypyrrol films in solutions containing ascorbic acid

Electrochromism and Swelling of Polypyrrole Membranes: An Electrochemical and Ellipsometric Study

“…The optical indices of the substrate were obtained at open circuit in the aqueous electrolyte, from the ellipsometric parameters of the polished gold electrode. The resulting values were in good agreement with previously reported data [15,28,29].…”

“…On the other side, at a relatively very low potential, Ea = 0.9 V, a thick Ppy layer grows. Its thickness is about 80 nm and an initial very low optical density similar to that of the electrolyte increases with the number of cycles [15]. In the case of Ppy/SDS, the initial cycles show a very low optical density at Ea = 1.2 V, and the mean thickness of the initial dispersed attached oligomer increases for increasing Ea = 1.4 V. In this electrolyte, the monomer is extensively dissolved into the SDS micelles, and the electro polymerisation leads towards an initially more dispersed film than in PO −3 4 solution.…”

“…Polypyrrole (Ppy) shows high permeability and selectivity for the detection of catecholamines in different electrolytes owing to anionic species exclusion by the interaction with negative charges into the film [14][15][16][17][18].…”

“…Ellipsometry can be applied "in situ" to characterise the layer structure seeing that the optical signal is very sensitive to the modifications produced by the polarisation of the electrode. Recent work has investigated the characteristics of electrodeposited Ppy on gold in buffer phosphate solution [15].…”

Electrochemical and optical study of the confined aqueous layer adsorbed on gold electrodes cycled in phosphate and dodecylsulphate solutions

“…Experimental conditions were similar to those described in a previous work [11][12][13]. The electrode was made by fitting axially a polycrystalline gold plaque (99.99 % purity, 1.5 mm thick) into a Teflon sheath.…”