(463f) On the Properties of Uniform Magnetic Microcomposites Assembled Via Microfluidic Spray Drying

A microfluidic jet
spray, which produces single trajectory droplets having identical thermal
history, was used to obtain monodisperse particles with precise morphology. The
method employed a moderate temperature range (£ 300^oC), and was able to handle multi-component precursors to
form solid particles in a single step. A stable colloidal suspension containing
iron chloride, lactose, and silica nanoparticles was processed to produce
microcomposites with a platelet-like morphology due to the nanoparticles.
Calcination caused the formation of iron oxide crystals of 10 nm to 1 μm
on the surface of the particles (Figure 1). The calcination period and the
post-drying conditions both affected the magnetic properties of the product and
it was found that the increase in magnetization correlated well with the
proportion of magnetite. This work demonstrates that microfluidic spray drying
is a versatile route for synthesising functional particles, being scalable with
sufficient yield for practical use and easy product recovery, while allowing
for subsequent processing if necessary. The reaction pathways occurring in the
particle formation are discussed.

Figure 1 - Schematic diagram
of the possible scenario for crystal formation on the particle surface.