Effect of tunicated Allium cepa bulb leaf activated biochar on polyvinyl alcohol composite shielding material for electronics applications.

In this study, a tunicated onion (Allium cepa) bulb leaf biochar-filled PVA-based composites were developed and characterized. The main aim of this study was to find the effect of tunicated onion bulb leaf biochar addition in activated and non-activated form into the PVA and its EMI shielding effect against high frequency bands. The composites were prepared by solution casting method and analyzed according to the ASTM standards. The results of this investigation reveal that the incorporation of non-activated biochar particle yields a maximum dielectric constant of 4.7, 2.1, 0.4, and 0.2 with a dielectric loss of 0.42, 0.44, 0.58, and 0.56 at 8, 12, 16, and 20 GHz for 5 vol.% of biochar in PVA (PB3). But the addition of activated biochar at 1, 3, and 5 vol.% increased the EMI shielding effect. The EMI shielding values are improved by 26%, 34%, 52%, and 40% at 8, 12, 16, and 20 GHz, for PB13 composite on compare with plain PVA. Similarly, the composite designation PB2 has highest tensile strength of 58 MPa, hardness of 74 shore-D, and the % of elongation of 84. SEM fractography reveals that the inclusion of activated biochar improved the interaction between matrix and particle with higher toughness. These agriculture wastes derived biochar-based flexible PVA EMI shielding composites could be used in telecommunication, aviation, medical gadgets, and electronic industries. [ABSTRACT FROM AUTHOR]