title: Macroporous polymers obtained in highly concentrated emulsions stabilized solely with magnetic nanoparticles.
abstract: Magnetic macroporous polymers have been successfully prepared using Pickering high internal phase ratio emulsions (HIPEs) as templates. To stabilize the HIPEs, two types of oleic acid-modified iron oxide nanoparticles (NPs) were used as emulsifiers. The results revealed that partially hydrophobic NPs could stabilize W/O HIPEs with an internal phase above 90%. Depending upon the oleic acid content, the nanoparticles showed either an arrangement at the oil-water interface or a partial dispersion into the oil phase. Such different abilities to migrate to the interface had significant effects on the maximum internal phase fraction achievable and the droplet size distribution of the emulsions. Highly macroporous composite polymers were obtained by polymerization in the external phase of these emulsions. The density, porosity, pore morphology and magnetic properties were characterized as a function of the oleic acid content, concentration of NPs, and internal phase volume of the initial HIPEs. SEM imaging indicated that a close-cell structure was obtained. Furthermore, the composite materials showed superparamagnetic behavior and a relatively high magnetic moment.
authors: Institute for Advanced Chemistry of Catalonia, Consejo Superior de Investigaciones Científicas (IQAC-CSIC), CIBER de Bioingeniería, Biomateriales y Nanomedicina, Jordi Girona 18-26, 08034 Barcelona, Spain. avvqst@cid.csic.es
authors: Alejandro
authors: A
authors: Vílchez
authors: Carlos
authors: C
authors: Rodríguez-Abreu
authors: Jordi
authors: J
authors: Esquena
authors: Angelika
authors: A
authors: Menner
authors: Alexander
authors: A
authors: Bismarck
mesh_terms: D004655:Emulsions; D005290:Ferric Compounds / Q000737:chemistry*; D059346:Magnets / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D005290:Ferric Compounds; D011108:Polymers; D014867:Water; C000499:ferric oxide; D019301:Oleic Acid