Synthesis and Characterization of Thermosensitive PNIPAM Microgels Covered with Superparamagnetic γ-Fe2O3 Nanoparticles

• Published in: Langmuir Vol. 23; no. 20; pp. 10280 - 10285
• Main Authors: Rubio-Retama, Jorge, Zafeiropoulos, Nikolaos E, Serafinelli, Caterina, Rojas-Reyna, Rosana, Voit, Brigitte, Lopez Cabarcos, E, Stamm, Manfred
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 25.09.2007
• Subjects: Acrylic Resins - chemistry; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Ferric Compounds - chemistry; Gels; General and physical chemistry; Magnetics; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Nanoparticles; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Surface physical chemistry; Temperature; Drug; Transition temperature; Iron oxide; Swelling; Nanoparticle; Hybrid material; Transition element compounds; Temperature effect; Superparamagnetism; Potential; Phase transitions; Characterization; Synthesis; Magnetic material
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la7009594

In the present study we report a facile and reproducible method of preparing magnetic thermosensitive hybrid material based on P(NIPAM) microgels covered with γ-Fe2O3 nanoparticles of 6-nm size. The iron oxide nanoparticles provided magnetic response to the microgels. In addition, the presence of the magnetic nanoparticles on the microgels altered their swelling behavior and shifted their volume phase transition temperature to higher values. In particular, for inorganic shells with 18% (w/w) of magnetic nanoparticles the volume phase transition of the microgels was shifted from 36 to 40 °C. In contrast, for shells consisting of 38% (w/w) magnetic nanoparticles the volume phase transition of the microgels was almost blocked, thus indicating that the microgel thermal response was strongly affected by the presence of the inorganic nanoparticles. The synthesized thermosensitive magnetic microgels are envisaged to be ideal for potential applications as thermosensitive targeted drug delivery systems.