A Comparative Study of Characteristics of Ferrogels Prepared using Coated and Uncoated Fe 3 O 4 Nanoparticles
- PDF / 300,872 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 62 Downloads / 167 Views
1234-QQ08-09
A comparative study of characteristics of ferrogels prepared using coated and uncoated Fe3O4 nanoparticles Kamlesh J. Suthar1, 2, Muralidhar K. Ghantasala 1, Derrick C. Mancini2, and Jan Ilavsky3 1 Department of Mechanical and Aeronautical Engineering, Western Michigan University, 1903 W. Mich. Ave., Kalamazoo, MI-49008, U.S.A. 2 Center for Nanoscale Materials, 3 Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL-60439, U.S.A. ABSTRACT This paper presents the results of our analysis of ferrogels prepared using uncoated and polyvinylpyrrolidone (PVP)-coated magnetite (Fe3O4) nanoparticles. The N-isopropylacrylamide (NIPAM) based hydrogel is used with 15-25nm Fe3O4 nanoparticles different concentrations in the range 1.25 -14%. These samples were analyzed using Ultra Small Angle X-ray Scattering (USAXS), Transmission Electron Microscopy (TEM), and Direct-Current Superconducting Quantum Interference Devices (DC-SQUID) magnetometry. Samples prepared with polyvinylpyrrolidone (PVP) coated nanoparticles showed a better single particle distribution compared to uncoated samples. USAXS data indicated that the gels prepared using uncoated nanoparticles have a large two particle agglomerations. In both cases, the volume fraction of the particles in the gel is linearly proportional to the initial particle concentrations. The DC-SQUID magnetometry analysis indicated that the magnetic moment of the gel samples prepared with uncoated particles is ~ 2emu/g compared to ~1.5emu/g for coated particles. INTRODUCTION Ferrogel is a chemically crosslinked polymeric network that has a colloidal dispersion of magnetic nanoparticles. In the ferrogel, magnetic nanoparticles are attached to the polymer by different adhesive forces, resulting in direct coupling between magnetic and elastic properties. They elongate, contract, and deflect in response to the applied magnetic field. The use of a magnetic field as an external stimulus would reduce the response time for actuation compared to hydrogel. This entails hydrogels suitable for soft actuators in MEMS devices. Due to large spectrum of stimuli responsive functionality, the hydrogel functionalized magnetic nanoparticles are used for magnetic imaging to targeted drug delivery [1] in biomedicine. Nanocomposite gels becoming an attractive material due to capabilities and potential use for number of application from biological sciences to mechanical engineering. In this context, magnetic nanoparticle based gels are important for many applications such as targeted drug delivery systems. Recently, there is a developing interest in dual-responsive hydrogel, e.g. pHthermo, pH-electrical, pH-magnetic [2], thermal-magnetic [3], in the field of pharmaceuticals, medicine [1], drug delivery systems [4] etc. Immobilizing the magnetic nanoparticles into crosslinked polymeric network of the hydrogel produces nanocomposite gels. -Fe2O3, and Fe3O4 particles are magnetic nanoparticles, which are frequently used in the research. From applications point of view, the ne
Data Loading...
