Recent researches in EMI shielding have seen a shift from simple composite structures to multi-layered composite structures, foam-based architectures, and three-dimensional (3D) printed composite structures. Multi-layered structures allow tuning the absorption coefficient through a rational arrangement of functional fillers to construct a sandwich structure. The multiple interfaces can lead to scattering and polarization losses. Also, porous structures can enhance the shielding properties at low filler volume fraction, adequate impedance match, dielectric loss due to the trapped air in the pores, and scattering at multiple interfaces. Herein we have explored a combination of multi-layered structures using foams. EMI shielding performance of multi-layered architectures fabricated using different strategies (i.e., foam, and 3D printed structures) has been evaluated. CNT and rGO-Fe3O4 were chosen as conducting and lossy fillers, to be incorporated strategically in the multi-layered structure. To fabricate the multi-layered architecture, the rGO-Fe3O4 was incorporated in polyvinylidene difluoride (PVDF) and the CNTs in the polycarbonate (PC)- as the two outer layers of the architecture. Various strategies like PU-based film, foam, and 3D printed mesh containing CNTs were fabricated and sandwiched between the PC and PVDF composite films to develop multi-layered architecture with improved shielding performance. Amongst all the fabricated structures, the PU-CNT foam-based multi-layered structure showed a high shielding effectiveness (SET) value of -39 dB in K-band, with absorption-dominated shielding (91% and above). The results presented here begin to suggest that in-situ synthesized foam with non-uniform and dead pores enhances the shielding performance compared to 3D printed mesh structures or non-porous structures.
|Speaker Bio:||Dr. Suryasarathi Bose is an Associate Professor in the Department of Materials Engineering, Indian Institute of Science (IISc) Bangalore. Prior to joining IISc Bangalore as a faculty member in 2011, he was a postdoctoral researcher at Katholieke University of Leuven (Belgium), where he was hosted by Prof. Paula Moldenaers. He received his Ph.D. in Materials Engineering from the Indian Institute of Technology (IIT) Bombay.
Prof. Bose’s research interests include the design of membranes for water remediation and desalination, hybrid nanostructured material for heavy metal adsorption, structure-property correlation in polymer blends and nanocomposites, concentration fluctuation and segmental dynamics in multiphase systems, directed self-assembly using demixing in polymer blends as a tool, and materials for EMI shielding and microwave absorption. He is the recipient of many awards and accolades, including the prestigious Swarnajayanti Fellowship from the Department of Science and Technology (DST), Government of India, Professor Kaushal Kishore Memorial award of the SPSI, the Young Engineer Award from the Indian National Academy of Engineering (INAE), the Indian National Science Academy (INSA) Medal for Young Scientist, the Polymer Processing Society Young Scientist Award, the DAE-BRNS Young Scientist Research Award, and the Distinguished Young Rheologist Award from TA Instruments, USA. His research has been recognized by several esteemed bodies of national importance, including INAE, and the Indian National Young Academy of Science (INYAS), and the National Academy of Sciences India (NASI). He has published more than 200 research papers and has served on the editorial boards of many high-impact journals of international repute.