Stable, polymer-directed and SPION-nucleated magnetic amphiphilic block copolymer nanoprecipitates with readily reversible assembly in magnetic fields

Abstract

The formation of inorganic-organic magnetic nanocomposites using reactive chemistry often leads to a loss of super-paramagnetisim when conducted in the presence of iron oxide nanoparticles. We present here a low energy and chemically-mild process of co-nanoprecipitation using SPIONs and homopolymers or amphiphilic block copolymers, of varying architecture and hydrophilic/hydrophobic balance, which efficiently generates near monodisperse SPION-containing polymer nanoparticles with complete retention of magnetism, and highly reversible aggregation and redispersion behaviour. When linear and branched block copolymers with inherent water-solubility are used, a SPION-directed nanoprecipitation mechanism appears to dominate the nanoparticle formation presenting new opportunities for tailoring and scaling highly functional systems for a range of applications.

Self-assembly of amphiphilic poly(styrene-b-acrylic acid) on magnetic latex particles and their application as a reusable scale inhibitor

“…This implies that limited self-assembly of the collapsed hydrophobic polymer segments occurs during the solvent polarity switch. 30 When a polymer solution was added into a stable magnetic emulsion (12.0 w/v%) in which St and/or PS was retained on the droplets, the hydrophobic PS blocks adsorb onto the magnetic emulsion surface by the hydrophobic attractive force. Moreover, the St-rich phase may induce the PS blocks to strongly adsorb on the emulsion.…”

Branched and Dendritic Polymer Architectures: Functional Nanomaterials for Therapeutic Delivery

“…Additionally, it has been demonstrated that these highly branched polymers, synthesised by ATRP, can form stable nanoparticle composites with super-paramagnetic iron oxide nanoparticles (SPIONs) with future uses for delivery of drugs, imaging agents, or hyperthermia agents within cancer therapies. 111 Wang and coworkers have investigated the effect of branching on transfection of plasmid DNA coding for G-luciferase and also green fluorescent protein (GFP). 113 Variation of primary chain length and density of branching between individual polymer chains was achieved using ATRP with redox responsive divinyl comonomer.…”

Environmental implications and applications of engineered nanoscale magnetite and its hybrid nanocomposites: A review of recent literature

“…Hybrid Fe3O4-graphite composites [24] and hollow Fe3O4-Fe NPs with graphene sheets [25] have been prepared by in-situ chemical precipitation as high-performance electromagnetic wave absorbing materials. A recent study has explored low energy and chemically-mild process of co-nanoprecipitation using superparamagnetic iron oxide nanoparticles (SPIONs) and homopolymers or amphiphilic block copolymers, of varying architecture and hydrophilic/hydrophobic balance, which efficiently generates near monodisperse SPION-containing polymer NPs with complete retention of magnetism, and highly reversible aggregation and re-dispersion behavior [26]. One advantage of this method is that the quality of MNPs is reproducible.…”