不同铁盐氧化掺杂导电聚苯胺纳米结构的合成及性能研究

Synthesis and Properties of Polyaniline Nanostructures Using Different Ferric Salts

在没有外加掺杂剂的条件下,以FeCl3,Fe(NO3)3,Fe2(SO4)3,FePO4等多种铁盐为氧化剂,在水溶液中采用"无模板"的方法制备了具有较高电导率的聚苯胺纳米结构.铁盐是一种强酸弱碱盐,在水溶液中发生水解释放出质子,质子可以作为掺杂剂进入聚苯胺主链,因此,在苯胺的聚合过程中,铁盐同时起到氧化剂和掺杂剂的双重功能,进一步简化了导电聚苯胺纳米结构的合成条件,降低了反应成本.FTIR,UV-Vis,XRD等结构表征证实所得的纳米结构的聚苯胺均为掺杂态.试验发现,铁盐较低的氧化/还原电位使产物具有较小的直径和较高的电导率和结晶性.不同的对阴离子对聚苯胺产物的形貌有一定的影响,但对产物的结构和性能影响不大.铁盐与苯胺单体的比例对聚苯胺的形貌和电导率均有较大的影响.

Polyaniline （PANI） nanostructures with a high conductivity （ 10^-2 - 10^-1 S/cm） were synthesized by ＂template-free＂ method in the presence of different kinds of ferric salts, such as FeC13 , Fe （ NO3 ）3, Fe2（SQ）3, FePO4 as oxidants. The ferric salts, acting as strong acidic salts, will produce protons via hydrolysis,which could be used as dopant for PANI. The nanostructures characterized by FTIR, UV-Visible absorption and XRD spectra are identical to the emeraldine salt state of PANI. This method is more simple and cheap because ferric salts could act as both oxidant and dopant at the same time, resulting in omitting external dopant. Moreover,the resulting nanostructures show thinner diameter and higher crystallinity than those of the nanofiers oxidized by ammonium persulfate （APS） perhaps due to the low redox potential of ferric salts. It is found that the ratios of oxidant to aniline affected strongly the morphology and conductivity of PANI. The counter-anions have some influences on the PANI morphology,however have little effects on the structure and properties of PANI.