Title : Rubber composites with EMI absorption shielding performance
Abstract:
Contemporary societal developments demonstrate a pronounced orientation toward the advancement of sophisticated electrical and electronic technologies, which indubitably enhances the overall quality of human existence. However, the proliferation of electronic devices results in the concurrent accumulation of electromagnetic radiation within the surrounding environment. This phenomenon leads to electromagnetic radiation from one source creating interference with another, a condition termed electromagnetic interference (EMI). EMI can exert substantial detrimental effects on electronic equipment functionality, diminishing operational efficiency or precipitating complete system failure. Furthermore, the adverse impact of EMI on biological systems and human health has been well-documented. Contemporary research has identified EMI's influence on multiple health dimensions, encompassing reproductive, neurological, and developmental complications. Consequently, there exists an increasingly urgent need for the development of materials that provide effective shielding against unwanted electromagnetic interference.
In comparison to conventional solid metallic plate shielding solutions, rubber-matrix composites exhibit advantageous characteristics including reduced cost, lower density, enhanced processability and moldability, superior elastic properties, increased flexibility, and improved resistance to corrosive degradation.
In present work, composite materials were prepared by incorporation of manganese-zinc ferrite and combination of manganese-zinc ferrite with carbon black into acrylonitrile-butadiene rubber. The study was aimed at examination of fillers' influence on mechanical properties, electrical conductivity, and absorption shielding performance of the composites. The findings showed a strong correlation between permittivity, conductivity, and absorption shielding. Enhanced conductivity corresponded with increased permittivity, which consequently diminished absorption shielding effectiveness. The results demonstrated that composites filled with manganese-zinc ferrite can be used as efficient EMI shields with absorption dominated shielding mechanism within the tested frequency range 1 MHz – 3 GHz. In hybrid composites based on combination ferrite and carbon black, the inclusion of carbon black led to a more uniform distribution of ferrite throughout the rubber matrix and enhanced the composites' mechanical properties. Additionally, the conductive carbon black played a role in charge storage, various polarization processes, and associated relaxation effects within the rubber matrix, which resulted in increased permittivity. These changes subsequently influenced the absorption peaks and related EMI absorption characteristics of the hybrid composites.
