Improved Electromagnetic Interference Shielding Properties of MWCNT-PMMA Composites Using Layered Structures.

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Electromagnetic interference (EMI) poses a significant challenge in electronic devices.
• Developing lightweight and effective EMI shielding materials is crucial for modern technology.
• Carbon nanotube-polymer composites are promising candidates for EMI shielding applications.

Purpose of the Study:

• To evaluate the EMI shielding effectiveness (SE) of multi-walled carbon nanotubes-polymethyl methacrylate (MWCNT-PMMA) composites.
• To compare the performance of composites prepared via different fabrication techniques.
• To assess the mechanical properties of the developed shielding materials.

Main Methods:

• Preparation of MWCNT-PMMA composites using two distinct techniques.
• Measurement of EMI shielding effectiveness in the X-band frequency range (8.2-12.4 GHz).
• Characterization of mechanical properties, including tensile and flexural strength and modulus.

Main Results:

• Achieved EMI SE up to 40 dB with stacked thin MWCNT-PMMA films (seven layers, 0.3 mm thick).
• Achieved EMI SE up to 30 dB with stacked thicker MWCNT-PMMA bulk composite (two layers, 1.1 mm thick).
• EMI shielding mechanism in the X-band is dominated by absorption.
• Mechanical properties were comparable to or better than the pure PMMA polymer.

Conclusions:

• MWCNT-PMMA composites exhibit significant potential as high-performance EMI shielding materials.
• The composite's structural integrity, combined with its shielding capabilities, makes it suitable for demanding applications.
• Fabrication method and layer configuration influence the overall EMI shielding effectiveness.