Assembly of magnetic microcomposites from low pH precursors using a novel micro-fluidic-jet-spray-dryer

► Production of monodisperse magnetic microcomposites using a micro-fluidic-jet spray dryer. ► Low pH precursors containing iron(III) salt, lactose, and silica nanoparticles. ► Bowl-like microparticles with the addition of silica nanoparticles. ► Formation of iron oxide crystals upon secondary heat treatment. ► Increasing magnetic strength with longer calcination period due to larger iron oxide crystals on the surface.