Synthesis and Characterization of Poly(Acrylic Acid) Coated Magnetite

Poly(acrylic acid) (PAA) coated magnetite was prepared via simple one-step method and its properties were evaluated. The PAA coated magnetite particles were synthesized with co-precipitation of FeSO₄ and FeCl₃ in the presence of PAA of various molecular weight. The obtained samples were collected by permanent magnet, and characterized with XRD and SEM. The total coated PAA amount and free carboxy group in PAA were determined by TGA and neutralization titration, respectively. From the results of XRD and SEM, the magnetite nanoparticles were successfully synthesized regardless of the existence of PAA. The crystalline size of magnetite became large with increase of PAA molecular weight. In addition, both of the total coated PAA amount and free carboxy group increased with increase of PAA molecular weight.