Efficient preparation of carboxyl-functionalized magnetic polymer/Fe3O4 nanocomposite particles in one-pot miniemulsion systems

Abstract Magnetic polymer/Fe 3 O 4 nanocomposite particles (NCPs) have been widely used for many advanced applications. It is still a great challenge to efficiently synthesize polymer/Fe 3 O 4 NCPs through a simple and convenient technique. In this work, carboxyl-functionalized polymer/Fe 3 O 4 NCPs were efficiently and conveniently prepared through a one-pot miniemulsion polymerization by using methacrylic acid (MAA) as the functional comonomer and adopting a special use strategy of emulsifiers. The influence of synthesis parameters on the formation efficiency of polymer/Fe 3 O 4 NCPs was quantitatively evaluated in terms of the number fraction of polymer/Fe 3 O 4 NCPs ( f NCP ). The f NCP value in the as-synthesized emulsion reached above 80%. The interaction between MAA and Fe 3 O 4 magnetic nanoparticles (MNPs) in the oil phase could promote the homogenous distribution of Fe 3 O 4 MNPs among monomer droplets, while the interaction between the MAA monomeric units of copolymers and Fe 3 O 4 MNPs could confine the Fe 3 O 4 MNPs in the NCPs. Both interactions are beneficial to the formation of polymer/Fe 3 O 4 NCPs. The controlled mergence between the monomer droplets and latex particles could also lead to the consumption of plain monomer droplets, and furthermore improve the formation of polymer/Fe 3 O 4 NCPs.