Fig. 3.

Release of a model compound, ¹⁴C-DS, from PB-containing films held at a constant potential of 1.25 V. All films are (LPEI/PB/LPEI/¹⁴C-DS)₃₀. (a) Films held constant at 1.25 V (filled diamonds) or no applied potential (open diamonds) are shown. (b) Serial ¹⁴C-DS release from two (LPEI/PB/LPEI/¹⁴C-DS)₃₀ films in a single solution. One film was held at the oxidizing potential for 10 min, followed by 10 min below the oxidizing potential. Next, the process was repeated with a second film in the same degradation bath. Periods during which an oxidizing potential was applied are shaded.^{¶ ‖} (c) Release rate versus time for the films in b.** In all cases, error bars represent one standard deviation in measured values.