Synthesis Of Polyaniline Hollow And Plate-like Hierarchical Structure

The usual preparation methods of polyaniline hollow spheres are “hard template”,“soft template”,“no template” and so forth, among which “no template” method hasthe advantage of no follow-up treatment; compared with the hard templates, softtemplate can be easily removed by water or ethanol wash, and would not impose anyaggregate impact to the morphology of the product, and has become the focus forresearchers.In this paper, hierarchical structure polyaniline has been synthesized via “softtemplate chemical oxidation” method with aniline as monomer, ammonium persulfateas oxidant in the solution of myristic acid（MYA）, CoSO₄and perfluoro caprylicacid（PFOA）. The factors and mechanism of PANI micro/nanostructures were alsobeen investigated. The main contents are listed:1) Hollow sphere-like polyaniline was synthesized by “soft template” method:we used MYA to stablize aniline droplets in deionized water; it was found that when[MYA]=0.0044M,[ANI]=0.016M,[APS]/[ANI]=1:1, T=75℃, the PANIsythesised was fiber wrapped in mircosphere or bluk, and when [ANI]=0.022M,there were some10μm length sealled pipette-like PANI, as well as hollow sphere;and some sphere could be beaded.2) Hollow PANI multilevel structure was synthesized by “micelle-control”method: in the first place, complex micelles about400nm from the interaction ofcobalt sulfate （CoSO₄7H2O） and aniline were formed; When [ANI]=0.5M,[CoSO₄7H₂O]/[ANI]=1:1, T=0℃, polyaniline hollow sphere, diameter rangefrom1to2μm, with short fibers（100nm in length,20nm in diameter） on its surfacewas acquired.3) Super-hydrophobic PANI flake multilevel structure was synthesized by“self-assembly” method: PFOA/Aniline salt micelles, which were prepared by thereaction between low-surface energy PFOA and aniline, guided the synthesis of PANImicro/nanostructures. When [PFOA]=0.0024M,[ANI]=0.022M, T=25℃,[APS]=[ANI], the synthesized PANI was a sheet structure about tens of micrometers inlength and2-5μm in width, in which the surface of sheet structure was composed ofPANI fiber（about1μm in length）. When [ANI]=0.044M, the synthesized PANI was asheet structure of about20μm in length and2-3μm in width, in which the surfacewas covered with short thick irregular fibers. The water contact angles of bothstructues were149°and151°, respectively. In addition, it was a peak at2θ=6.2°in XRD graph of PANI, which illuminated that the product had a better orderedstructure.