Development of highly flexible electromagnetic interference shielding composites for electronic applications using Cobalt/ Hevea brasiliensis seed husk carbon dots/Bamboo microfibre-polyvinyl alcohol

Abstract

In this present work a highly flexible electromagnetic interference (EMI) shielding composite was prepared from industrial crop for advanced engineering applications. The EMI shielding composite product was further tested for its effectiveness on high frequency bands of 8–20 GHz. Through pyrolysis, the leftover rubber seed hulls were converted into carbon dots (C-dots). The composites were characterized after being made using the solution casting process. The inclusion of carbon dots increased the relative permittivity up to 9.4 with the lowest loss factor of 0.62 at 8 GHz, according to the findings. The hysteresis loop showed a broader "S" curve for cobalt with biochar at a 2 vol% concentration. Additionally, the composite contains 3 vol% of cobalt/carbon dots records a maximum tensile strength of 54.7 MPa, modulus of 0.88 GPa, and % of elongation of 128.7. However, the composite contains 5 vol% of cobalt/carbon dots (PBC4) had a total EMI shielding effect of − 54.3 dB at 20 GHz. These enhanced EMI shielding composites with highly retained flexibility could be employed as a protective material in telecommunication; chip sets manufacturing, defense and medical applications. • Carbon dots were successfully prepared from waste rubber seed hulls. • Cobalt/C-dots compound structure PVA composite prepared. • Measurement of total EMI shielding efficiency is improved for 2 vol% Co/C-dots. • The total EMI shielding up to − 54.7 dB was measured for Ku band. • The tensile and hardness properties measures 45% of improvement.