极低逾渗阈值的导电聚苯胺纳米复合膜

Electroconductive polyaniline nano-composite films with an extremely low percolation threshold

直接将改进的微乳液聚合法合成的纳米聚苯胺分别与聚乙烯醇和聚丙烯酰胺进行溶液共混复合，浇铸成纳米聚苯胺复合膜，研究了聚苯胺的加入量对复合膜的电导率的影响．所得复合膜的电导率符合逾渗规律，且导电膜的逾渗闽值极低，为0．04％左右，其中PVA纳米复合膜出现了双逾渗行为．加入极少量的聚苯胺即可使膜的导电率发生突跃，使其从绝缘体转变成半导体或导体．逾渗阈值下的复合膜不仅力学性能良好，而且透明性接近于纯基体膜，当膜中的聚苯胺质量分数为0．1％时，PVA复合膜对300～700nm波长的可见光的透过率为70％～84％．

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.