Percolation-Driven Optimization of MWCNT/CoMn₂O₄/PVA Metacomposites for Electromagnetic Wave Absorption and Interfacial Hydrophobicity in Optoelectronic Applications

The escalating demand for multifunctional nanomaterials in electromagnetic interference (EMI) mitigation and optoelectronic applications has highlighted the need for materials with optimized electromagnetic absorption and tailored surface properties. A significant challenge is enhancing electromagnetic wave absorption while controlling interfacial wettability to enable practical deployment in diverse environments. This study addresses these issues by synthesizing MWCNT/CoMn₂O₄/PVA metacomposites (MCP1-MCP5) with MWCNT weight fractions from 0.011 to 0.166 using in situ polymerization, followed by characterization via FESEM, BET/BJH, and electromagnetic testing (0-100 MHz). Results demonstrate that MCP3 (0.044 MWCNT) achieves the lowest reflection loss (∼-32.908 dB at 10 MHz, 1 mm thickness) 78 and a contact angle of ∼39°, indicating moderate wettability. MCP5 (0.166 MWCNT) exhibits an AC conductivity of 8.8 × 10^-3 at 100 MHz, enhancing absorption through improved conductive losses. These findings reveal percolation-driven tunability, positioning these metacomposites as promising candidates for EMI absorption and surface-engineered optoelectronic applications.