New Functions of Polyolefin for Manipulated Magnetic Nanostructures

The novel function of an old-fashioned plastic additive, i.e., Maleic anhydride grafted polypropylene (MAPP), has been demonstrated with simultaneously controlling the size, shape, crystalline phase, and self assembly patterns of magnetic nanostructures. Specifically, MAPP was utilized as polymeric surfactant to fabricate stable iron oxide / cobalt nanoparticle colloids through an in-situ one pot bottom-up method. By simply varying the ratio of MAPP to organometallic precursor, such as Fe(CO)₅; or changing the back bone chain length of MAPP, such as numerical molecular weight of 800 and 2500 g/mole, the as prepared iron oxide or cobalt nanoparticles with tunable crystalline phases can be achieved; which has rarely been reported before through the bottom up method. In addition, the different crystalline phases and self assembly patterns can in turn lead to significant differences in the magnetic property of these magnetic nanostructures. The formation mechanisms were proposed and discussed in detail.