Co/Co₃O₄ Based Nanoparticles and Their Polymer Composites for Tuned Electromagnetic Interference Shielding...

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetics

Background:

• Magnetic nanoparticles (NPs) are crucial for electromagnetic interference (EMI) shielding in electronic devices.
• Cobalt/cobalt oxide nanoparticles (Co/Co₃O₄ NPs) offer potential for advanced EMI shielding applications.

Purpose of the Study:

• To synthesize coconut oil and PVA capped Co/Co₃O₄ NPs using a chemical reduction method.
• To investigate the effect of surfactant ratios on NP size and oxidation state.
• To evaluate the EMI shielding behavior of Co/Co₃O₄ NPs impregnated in a polymer matrix.

Main Methods:

• Chemical reduction synthesis of Co/Co₃O₄ NPs.
• Characterization of NPs for phase (hcp, fcc), size (7-10 nm), and oxidation state.
• Impregnation of NPs into a polyvinyl alcohol (PVA) polymer matrix.
• Analysis of EMI shielding efficiency using a vector network analyzer (VNA) in X- and K_u-bands (8-18 GHz).

Main Results:

• Coconut oil capped Co/Co₃O₄ NPs were successfully synthesized with hcp and fcc phases.
• Varying surfactant ratios influenced NP size and oxidation state.
• EMI shielding efficiency increased with higher concentrations of Co/Co₃O₄ NPs in the PVA nanocomposites.

Conclusions:

• Co/Co₃O₄ NPs are effective for EMI shielding applications.
• Nanocomposite materials incorporating these NPs demonstrate enhanced shielding performance.
• The study highlights the potential of tailored magnetic NPs for electronic device protection.