EMI Shielding Properties of Sub-micron Polymer Composite of Barium Strontium Titanate Loaded with Polystyrene, Graphite Powder, and Carbon Fibre

Ever burgeoning demand for superlative performance has necessitated enhancement in the density of electronic components in the modern high-frequency equipments. However, this augmented density of components makes the instrument susceptible to electromagnetic interference (EMI) and the same is known to cause degradation in its performance. Literature reports indicate widespread usage of several polymer composites as shielding material for reducing EMI. In the present work, a unique composition of barium strontium titanate (Ba0.8Sr0.2TiO3 or BST) ceramic filler is used and its effect in reducing EMI shielding applications is studied. The investigation involves EM shielding studies on non-conducting polystyrene (PS) polymer-based composite with barium strontium titanate (PS/BST), graphite powder (PS/BST/GR), and carbon fibre (PS/BST/CF) synthesised via solvent method. The synthesised polymer composites are characterised using SEM, FTIR, and XRD techniques. It is interesting to note that the presence of graphite powder and carbon fibre-based polymer composite leads to microwave absorption-dominated shielding effect. The effectiveness in shielding values is demonstrated to increase from 1.28 to 8.01 dB and 1.28 to 13.07 dB after incorporation of graphite and carbon fibre in polystyrene/barium strontium titanate polymer composite, respectively, at 10 GHz frequency.