Shell morphology of core-shell latexes based on conductive polymers

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