Influence of ultrasonically assisted synthesis on particle size of magnetic nanoparticles

•Ultrasonication was applied for in situ synthesis of PMAA coated magnetite particles.•The uncoated and PMAA-coated magnetite particles showed similar magnetic properties.•The volume weighted mean size of PMAA coated magnetite particles was about 80 nm.

Poly(methacrylic acid)(PMAA) coated magnetite (Fe3O4) nanoparticles were synthesized via co-precipitation in aqueous solution with the use of conventional magnetic stirring and ultrasonic agitation. It has been shown that the ultrasonic agitation during the synthesis of magnetite particles decreased the size of PMAA-coated magnetic agglomerates significantly. The primary particle size of iron oxide particles was determined as approximately 10 nm by X-ray diffraction method (Scherer's equation). The volume weighted mean size (D[4,3]) of PMAA coated magnetite particles was determined as about 80 nm using laser diffraction technique.