Modulating the interfacial properties of magnetic nanoparticles through surface modification with a binary polymer mixture towards stabilization of double emulsions

摘要

The combination of multiple functionalities in a single material is an interesting strategy for the emergence of new properties and consequently for improving its potential applications. We report here the preparation and surface modification of magnetic iron oxide nanoparticles by simply grafting a binary mixture of poly(ethylene oxide) and polymethylmethacrylate in order to modulate the nanoparticles surface properties and their interfacial properties. We demonstrate that the nanoparticles assembly and colloidal stability can be modulated by the polymers composition that afterwards reflects on their adsorption efficacy at water-oil interfaces. The binary-coated particles interestingly formed stable emulsions evidencing their effective amphiphilic character. These emulsions were characterized as oil-in-water and, particularly with polymer mixtures, double (water-in-oil-in-water) emulsions were obtained. Because of the use of magnetic nanoparticles, these emulsions are responsive to an external magnetic field pointing out to an interesting system with potentially applications in different areas and validating this methodology as a versatile approach to incorporate surface functionalities to iron oxide nanoparticles.