Authors: Y-F Huang, C-W Lin
Affilation: National Yunlin University of Science and Technology, Taiwan
Pages: 711 - 714
Keywords: polyaniline, nanofibers
This study reports the synthesis of polyaniline (PANI) nanofibers with an average diameter of 30~50 nm using HCl as a dopant. Experiments controlled the polymerization rate in terms of temperature and oxidant concentration. Transmission electron microscopy (TEM) reveals the formation mechanism of PANI nanofibers. The polymers formed nanofibers in the early stages of polymerization for all polymerization states. However, as the reaction continued, these primary nanofibers exhibited different formation behaviors. In the cases of low polymerization rates, the primary nanofibers continued growing and then turned into agglomerates with irregular shapes. In contrast, aggregation can be effectively prevented under a high polymerization rate, thus preserving PANI nanofibers in the final product. These results imply that PANI nanofiber formation may be an intrinsic characteristic of polymerization, and the growth mechanism can be described as follows: (1) intrinsic PANI nanofiber formation in the initial reaction stages, and (2) secondary growth of the initially formed nanofibers. Evidence shows that the secondary growth behavior of PANI nanofibers is greatly dominated by the reaction rate.