Understanding of electrochemical and structural changes of polypyrrole/polyethylene glycol composite films in aqueous solution

► Electrochemical monitoring of PPy and PPy-PEG films over immersion time. ► Electrochemical and surface analysis showed that PEG improves the stability of PPy films. ► Mott-Schottky analysis reveals p-type conductance for both films. ► In situ AFM analysis sustains electrochemical behaviour. ► A model of PPy and PPy-PEG films behaviour during immersion was elaborated.