Electrostatic Self-Assembly Of Iron Oxide/Polyaniline Core-Shell Nanoparticles

Polyaniline (PANI) is considered one of the most multifunctional polymers, due to its low price, good conductivity, environmental stability and unique oxidation-reduction quality. Iron oxide is widely used in various fields for its broad chromatogram, non-toxic, low cost advantages. Because of the "interfacial reinforcing effect", metal oxide/polyaniline composite materials have broder application prospects in some areas, such as in quantum device, magnetic recording material, sensor, capacitors, photocopy toner, conductive dope and rechargeable batteries.In this thesis, monodispersedα-Fe2O3 with pseudo-spherical shape andβ-FeOOH with spindle shape were prepared by forced hydrolysis of FeCl3, and the average sizes ofα-Fe2O3 andβ-FeOOH particles were 50 nanometers and 150 nanometers, respectively. The isoelectric point ofα-Fe2O3 andβ-FeOOH were pH=4.5 and pH=6.0, respectively.The polyaniline (PANI) nanoparticles were synthesized by chemical oxidation method. TEM, FT-IR, UV-Vis and cyclic voltammetry were used to characterize these polyaniline particles. The PANI nanoparticles with the smallest size were obtained when poly (sodium 4-styrenesulfonate) (PSS) was used, and the average size of PANI nanoparticles was 15 nanometers.α-Fe2O3PANI andβ-FeOOH/PANI core-shell nanoparticles were prepared by layer-by-layer electrostatic self-assembly technology, through the surface modification ofα-Fe2O3,β-FeOOH and PANI nanoparticles. TEM, FT-IR, UV-vis and cyclic voltammetry were also used to characterize these core-shell nanoparticles. The effects of pH values, packaging temperature and reaction time on the structure of core-shell particles were discussed.