Size-tunable carboxylic functionalized Fe3O4 nanoparticle and evaluation of its magnetic and dispersion properties

The surface functionalization for Fe3O4 nanoparticles must be accompanied by the properties necessary for the realization of the driving force for surface attachment of organic or inorganic materials. In this study, the morphological and physicochemical behaviors of carboxylation of clustered Fe3O4 nanoparticles with carboxyl polymer precursors, polyacrylic acid, were discussed. The surface functionalization affects the binding energies of the primary particles that maintain the cluster structure, leading to a dramatic change in morphology as the imbalance was caused. As a result, the size of the nanoclusters was controlled according to the content of the precursors, and the recombination for the stabilization of the peeled off primary particles were occurred. Thus, a suitable precursor composition for the carboxylation had been derived. Furthermore, it improved the dispersibility according to the activity of the surface characteristics and caused a change in the magnetic property as the relative size and cluster density decreased. •Magnetic nanoparticles had been dispersed via carboxylic functionalization.•Amount of PAA affected to the amount of surface charge.•Scabrous shape had formed by excess repulsive force at high amount of PAA.•Size of Fe3O4 was varied from 387 to 175 nm at 1–15 wt% of PAA.