(7eq) Magnetic Polymer Nanocomposites for Giant Magnetoresistance and Electromagnetic Shielding

Due to the incomparable advantages such as light weight, optical, magnetic and enhanced mechanical properties, polymer nanocomposites have been widely studied by the researchers for different applications such as environmental remediation, energy (or information) storage and sensing.^1-4 Giant Magnetoresistance (GMR) phenomenon can be designed for information storage, our previous work shows that polymer nanocomposites show unique GMR behavior, indicating great potential applications for information storage.⁵ Meanwhile, as the development of electrical devices, the electromagnetic wave radiation is a potential threat for human being’s health.¹Thus, the materials with electromagnetic wave absorption are urgently needed. In this project, we found the negative GMR in the magnetite polypyrrole nanocomposites synthesized by the surface initiated polymerization method. The temperature dependent resistance of the magnetite nanocomposites indicates a 3-D variable range hopping (VRH) electrical conduction mechanism. The positive GMR is observed in the synthesized pure polypyyole at room temperature and analyzed by the wave function shrinkage model. The negative MR is obtained in the synthesized magnetic PNCs at room temperature and analyzed by the orbital magnetoconductivity theory. Meanwhile, the enhanced electromagnetic wave shielding is observed in its epoxy nanocomposites, which is due to the increased interface area, eddy current loss and increased anisotropic energy. Moreover, the significantly reduced flammability is observed and analyzed as well.

Research Interests:

• Conductive Polymers

• Polymeric Giant Magnetoresistance Materials

• Environmental Remediation Polymers

• Electromagnetic Interference Shielding/Microwave Absorption Composites

Teaching Interests:

• Thermodynamics

• Fluid dynamics

• Advanced materials processing

Reference:

1. J. Guo, H. Song, H. Liu, X. Liu, C. Luo, X. Zhang, J. Kong, Z. Guo, Y. Ren, T. Ding, M. A. Khan and D. P. Young, Journal of Materials Chemistry C, 2017, DOI: 10.1039/C7TC01502J.

2. J. Guo, L. Guan, H. Wei, M. A. Khan, X. Zhang, B. Li, Q. Wang, B. L. Weeks, D. P. Young, T. Shen, S. Wei and Z. Guo, Journal of The Electrochemical Society, 2016, 163, H664-H671.

3. H. Gu, J. Guo, H. Wei, S. Guo, J. Liu, Y. Huang, M. A. Khan, X. Wang, D. P. Young, S. Wei and Z. Guo, Advanced Materials, 2015, 27, 6277-6282.

4. B. Qiu, J. Guo, X. Zhang, D. Sun, H. Gu, Q. Wang, H. Wang, X. Wang, X. Zhang and B. L. Weeks, ACS applied materials & interfaces, 2014, 6, 19816-19824.

5. J. Guo, H. Gu, H. Wei, Q. Zhang, N. Haldolaarachchige, Y. Li, D. P. Young, S. Wei and Z. Guo, The Journal of Physical Chemistry C, 2013, 117, 10191-10202.