Ceramic based multi walled carbon nanotubes composites for highly efficient electromagnetic interference shielding

In this work, for the first time a highly conductive ceramic composite was made by incorporating multi-walled carbon nanotubes (MWCNT) in aluminum (Al)/alumina (Al₂O₃) matrix by a simple mechanical mixing technique. The different weight percentage (wt%) of MWCNT incorporated with Al/Al₂O₃ and their role on the electrical and electromagnetic interference shielding effectiveness (EMI SE) of ceramic composites were investigated. The high electrical conductivity of 280 S/m was achieved for MWCNT@Al/Al₂O₃ composites with 8 wt% MWCNT content which is 280 times higher than MWCNT@Al/Al₂O₃ composites (1 S/m) with 1 wt% MWCNT. In addition, MWCNT@Al/Al₂O₃ sample showed a high EMI SE value of 46 dB for the X-band which is capable to block more than 99.9% of incident electromagnetic radiation. The high electrical conductivity and EMI SE properties of MWCNTs embedded ceramic composite system has originated from the homogenous distribution of conducting carbon nanotubes to form a percolated network at low filler loading. This work presents a strategy to develop a conductive ceramic composites for the excellent EMI shielding and electrical properties by a simple mechanical mixing approach.