Shell morphology of core-shell latexes based on conductive polymers

Core-shell latexes with a conductive shell can be used to prepare transparent conducting layers. We have focussed on the relation between the conducting polymer content and the shell morphology and on its influence on conductivity. At low polypyrrole (PPy) concentrations the shell has a smooth surface as is shown using SEM, and the conductivity correlates with the PPy content. The percolation threshold is 0.25 wt% PPy, indicating a theoretical shell thickness of 6ه. At higher PPy loadings different morphologies are formed and the conductivity is almost independent of the PPy content. TEM micrographs of sections of the dried conductive latex embedded in epoxy give the conclusive evidence for the core-shell structure.