(604f) Nanocomposite Fabrication through Particle Surface Initiated Polymerization

Magnetic nanoparticles (NPs) have attracted much interest due to their special physicochemical properties such as enhanced magnetic moment [1] and coercivity [2] different from the bulk and atomic counterparts. Incorporation of the inorganic NPs into a polymer matrix has extended the particle applications such as in high-sensitivity chemical gas sensor [3] due to the advantages of polymeric nanocomposites possessing high homogeneity, flexible processability and tunable physicochemical properties such as mechanical, magnetic and electrical properties.[4-6] High particle loading and flexible nanocomposites are required for certain applications such as electromagnetic wave absorber and solar cell. However, high loading always causes the brittleness and rigidity of the nanocomposite, even introduces the artificial defects such as air voids, which limits its application. In this project, nanoparticle surface initiated polymerization method by utilizing the physicochemical adsorption of the initiator onto the nanoparticle surface in tetrahydrofuran solution was adopted to fabricate the magnetic nanoparticle filled polyurethane nanocomposite. The obtained iron-oxide nanoparticles filled polyurethane nanocomposite exhibits highly flexible as compared with the brittle and rigid ones obtained from the direct mixing method. The particle loading can be tuned to up to 60 wt%. The reaction mechanism was investigated by FT-IR spectrophotometer, thermo-gravimetric analysis (TGA), XPS and TEM. The particle distribution was studied by SEM and AFM. The comparison of the magnetic and electromagnetic wave absorption properties between these two methods will be reported. The reported nanocomposite fabrication method is general and has the potential ability to be used in other nanoparticle and polymer systems.

References:

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[2] S. Gangopadhyay, G. C. Hadjipanayis, S. I. Shah, C. M. Sorensen, K. J. Klabunde, V. Papaefthymiou, and A. Kostikas, J. Appl. Phys., 70, 5888-90 (1991);

[3] H. Tang, M. Yan, X. Ma, H. Zhang, M. Wang, and D. Yang, Sensors and Actuators, B: Chemical B113, 324-328 (2006);

[4] Y. Lin, A. Boeker, J. He, K. Sill, H. Xiang, C. Abetz, X. Li, J. Wang, T. Emrick, S. Long, Q. Wang, A. Balazs, and T. P. Russell, Nature, 434, 55-59 (2005);

[5] V. Yong and H. T. Hahn, Nanotechnology, 15, 1338 (2004)

[6] Z. Guo, L. L. Henry, V. Palshin, and E. J. Podlaha, J. Mater. Chem., 16, 1772-1777 (2006).