Qiu Biwei, Wang Jingyun, Li Zhoujing, Wang Xia, Li Xiaoyan
School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Polymers (Basel). 2020 Feb 3;12(2):310. doi: 10.3390/polym12020310.
Polyaniline (PANI), a typical conducting polymer, has attracted great interest as an electrode material. A series of PANIs were prepared through fast microwave-assisted chemical oxidative polymerization with varying HCl and APS concentrations here. It was found that the microwave synthesized PANIs had 4 times higher for the yields and 710 times higher for the electrical conductivity in comparison to PANI samples prepared using conventional method. PANI nanosheets could easily be fabricated in weakly acidic solution due to their oligomeric structure, which contained flat phenazine rings. By contrast, linear PANI chains produced in highly acidic solutions formed nanofibers. The APS concentration did not significantly affect the molecular structures of PANIs under the conditions here. However, increasing the concentration of APS produced nanofibers with shorter branches, which may be due to secondary nucleation during chain growth resulting from increases in active initiation centers. The electrical conductivity and electrochemical performance of PANIs were both improved with increasing HCl and APS concentrations. Improvements due to increases in HCl concentration may be attributed to additions in conjugation length and enrichment of doping levels, while improvements due to increases in APS concentration could be attributed to the increased crystallinity of PANI, which facilitates ion transport.
聚苯胺（PANI）是一种典型的导电聚合物，作为电极材料引起了人们的极大兴趣。在此，通过快速微波辅助化学氧化聚合，使用不同浓度的盐酸（HCl）和过硫酸铵（APS）制备了一系列聚苯胺。结果发现，与采用传统方法制备的聚苯胺样品相比，微波合成的聚苯胺产率高出约4倍，电导率高出7至10倍。由于其低聚物结构包含扁平的吩嗪环，聚苯胺纳米片在弱酸性溶液中易于制备。相比之下，在高酸性溶液中产生的线性聚苯胺链形成了纳米纤维。在此条件下，APS浓度对聚苯胺的分子结构影响不显著。然而，增加APS浓度会产生分支较短的纳米纤维，这可能是由于链增长过程中活性引发中心增加导致二次成核所致。随着HCl和APS浓度的增加，聚苯胺的电导率和电化学性能均得到改善。HCl浓度增加带来的改善可能归因于共轭长度的增加和掺杂水平的富集，而APS浓度增加带来的改善则可归因于聚苯胺结晶度的提高，这有利于离子传输。
