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

Magnetic polymer/Fe3O4 nanocomposite particles (NCPs) have been widely used for many advanced applications. It is still a great challenge to efficiently synthesize polymer/Fe3O4 NCPs through a simple and convenient technique. In this work, carboxyl-functionalized polymer/Fe3O4 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/Fe3O4 NCPs was quantitatively evaluated in terms of the number fraction of polymer/Education in a Changing Wales NCPs (f(NCP)). The f(NCP) value in the as-synthesized emulsion reached above 80%. The interaction between MAA and Fe3O4 magnetic nanoparticles (MNPs) in the oil phase could promote the homogenous distribution of Fe3O4 MNPs among monomer droplets, while the interaction between the MAA monomeric units of copolymers and Fe3O4 MNPs could confine the Fe3O4 MNPs in the NCPs. Both interactions are beneficial to the formation of polymer/Fe3O4 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/Fe3O4 NCPs.