title: Magnetophoresis of iron oxide nanoparticles at low field gradient: the role of shape anisotropy.
abstract: Magnetophoresis of iron oxide magnetic nanoparticle (IOMNP) under low magnetic field gradient (<100 T/m) is significantly enhanced by particle shape anisotropy. This unique feature of magnetophoresis is influenced by the particle concentration and applied magnetic field gradient. By comparing the nanosphere and nanorod magnetophoresis at different concentration, we revealed the ability for these two species of particles to achieve the same separation rate by adjusting the field gradient. Under cooperative magnetophoresis, the nanorods would first go through self- and magnetic field induced aggregation followed by the alignment of the particle clusters formed with magnetic field. Time scale associated to these two processes is investigated to understand the kinetic behavior of nanorod separation under low field gradient. Surface functionalization of nanoparticles can be employed as an effective strategy to vary the temporal evolution of these two aggregation processes which subsequently influence the magnetophoretic separation time and rate.
authors.affiliation: School of Chemical Engineering, Universiti Sains Malaysia, Nibong Tebal 14300, Penang, Malaysia; Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA. Electronic address: chjitkangl@eng.usm.my.
authors.forename: Jitkang
authors.initials: J
authors.lastname: Lim
authors.affiliation: School of Chemical Engineering, Universiti Sains Malaysia, Nibong Tebal 14300, Penang, Malaysia.
authors.forename: Swee Pin
authors.initials: SP
authors.lastname: Yeap
authors.affiliation: School of Chemical Engineering, Universiti Sains Malaysia, Nibong Tebal 14300, Penang, Malaysia.
authors.forename: Chee Hoe
authors.initials: CH
authors.lastname: Leow
authors.affiliation: School of Chemical Engineering, Universiti Sains Malaysia, Nibong Tebal 14300, Penang, Malaysia.
authors.forename: Pey Yi
authors.initials: PY
authors.lastname: Toh
authors.affiliation: School of Chemical Engineering, Universiti Sains Malaysia, Nibong Tebal 14300, Penang, Malaysia.
authors.forename: Siew Chun
authors.initials: SC
authors.lastname: Low
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry / Q000302:isolation & purification*; D007700:Kinetics; D008280:Magnetics; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D054118:Nanospheres; D043942:Nanotubes
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide
keywords: Colloidal stability; Cooperative magnetophoresis; Low gradient magnetic separation; Magnetic nanoparticles; Shape anisotropy