Computational Study of Treated and Untreated Corn Husk Powder and Polycaprolactone for Microwave Shielding Using Finite Element Method

Introduction Microwave devices and communication devices produce electric fields which may be dangerous to surrounding applications. These field can be shielded using conductive shells that are closed on all sides. These close conductive shells are often designed using thin metal foils. However, for many applications these enclosures can add significant cost and weight to a product and a minute gap in the enclosure can completely damage the benefits of the enclosure. Moreso, the metal foil are not flexible to complex geometry. The solution to the gap identified is to use a material that is light, flexible and durable which can shield unwanted electromagnetic wave (EM) waves. For this work, treated and untreated corn husk powder (CHP) was produced from agricultural waste residues by grinding into powder form, while polycaprolactone (PCL) was commercially obtained. Method The composites of the materials were synthesized using melt blending technique. The dielectric property of the produced materials were investigated using open ended coaxial probe technique. The dielectric constant values was used in the computational study of the composites using finite element method. Result Results indicates that the dielectric property of the treated was greater than the untreated composites. The alkali treatment affected the value of the dielectric constant, shielding effectiveness, and transmission coefficients of the composites. The highest dielectric property obtained was 3.42 for the 30 % filler with a loss factor of 0.47. The filler played significant role in the values of shielding effectiveness (SE) obtained, where the highest filler was able to shield radiation by up to -4.21 dB at the frequency range measured. Conclusion From the electric field intensity, it was observed that the highest filler had the minimum transmitted intensity of 2185.87 v/m. Due to the high loss factor of 0.47 obtained for the 30 % filler content, waveguide terminators and other microwave components can be produced from this composite.