The electrically conducting nano-composite films with polyaniline (PAN) nanoparticles synthesized by a modified microemulsion polymerization were prepared by casting the blend of PAN nanoparticles waterborne latexes with traditional water soluble polymers such as polyvinyl alcohol (PVA) and polyacrylamide (PAM), respectively. The effect of the PAN loading on the electrical conductivity of the resulted films is studied in detail. It is found that the conducting behavior of the films obeys the percolation law and shows an extremely low percolation threshold of 0.04%, in which the PVA nano-composite films exhibit double percolation thresholds. The conductivity of the films increases dramatically even with adding an extremely small amount of PAN particles, simply realizing a transition from insulator to semiconductor or conductor. The films with PAN loading around the percolation thresholds have good mechanical performances and similar transparency compared with the pure matrix film. The transparency of the PVA film with PAN loading of 0.1% can reach 84% in a wavelength range of 300～700 nm.

polyaniline; nanoparticle; nano-composite film, electroconducting film; percolation threshold