Elaboration and characterization of cu based nanocomposites for electromagnetic interferences shielding

An electromagnetic interference (EMI) shielding is a material that attenuates radiated electromagnetic energy. Polymer nanocomposites are a class of materials that combine electrical, thermal, dielectric, magnetic and/ or mechanical properties, which are useful for the suppression of electromagnetic interference. In this work, we looked over the effectiveness of the electromagnetic interference shielding of polymer-based nanocomposites. These are thin slabs of epoxy resin strengthened with nanostructured Cu powders. Nanostructured Cu powders were obtained by mechanical milling using the high-energy RETSCH PM400 ball mill (200 rpm). A powder sampling was conducted after 3h, 6h, 12h, 24h, 33h, 46h and 58h milling for characterization requirements. XRD analysis via the Williamson-Hall method shows that the mean crystallites size decreases from 151.6 nm (pure Cu phase) to 13.8 nm after 58h milling. Simultaneously, the lattice strain increases from 0.1% (pure Cu phase) to 0.59% after 58h milling. The elaboration of thin slabs was performed by mixing a vol./3 fractions of nanostructured Cu powder, epoxy resin and hardener. Thin samples of 1 mm thickness were moulded for use in a rectangular wave-guide. The EMI shielding experimental involved a two ports S parameters cell measurement made of R120 metallic wave-guides of rectangular section (19.05x9.525 mm2) and operational over the frequency band of 9.84 to 15 GHz in association with a network analyser. Obtained results show moderate EMI shielding effectiveness for the milled Cu-based slabs. © 2021 Trans Tech Publications Ltd, Switzerland.