Enhanced Multifunctionality of Carbon Black-Modified Melamine Sponge: Flame Retardancy, Electromagnetic Wave Absorption, and Sensing Capabilities

This study investigates the multifunctional properties of a carbon black (CB)- and polyvinyl alcohol (PVA)-modified melamine sponge, focusing on flame retardancy, electromagnetic wave absorption, and sensing capabilities. Scanning electron microscopy analysis reveals the microstructural changes induced by CB modification, with CB particles forming a continuous layer on the sponge skeleton. Thermal analysis via thermogravimetric analysis and differential thermal analysis indicates increased residual mass with higher CB content, while Fourier transform infrared spectroscopy shows minimal alteration in the organic constituents post-modification. Flame-retardancy testing demonstrates enhanced flame suppression in CB-modified sponges, with residual char percentages of 26%, 72%, and 85% for the raw sponge, low-CB/sponge, and high-CB/sponge, respectively. Electromagnetic wave absorption performance is evaluated through impedance matching and reflection loss mapping, indicating the optimal thickness for absorption efficiency. Additionally, the high-CB/sponge exhibits promising sensing properties, accurately detecting human motions with high reproducibility and durability. Overall, the study highlights the multifunctional capabilities of CB-modified melamine sponge, making it a promising candidate for various applications requiring flame retardancy, electromagnetic wave absorption, and sensing functionalities.