Electrical Resistivity and Microwave Properties of Carbon Fiber Felt Composites

Abstract

We present studies on the microwave properties, electrical resistivity, and low-frequency (10 Hz–20 kHz) noise characteristics in the temperature range of 78 K to 380 K of composite materials made from bisphenol A-based epoxy resin and carbon fiber felts. Two types of carbon fibers were used, derived from polyacrylonitrile or regenerated cellulose. We show that these structures are suitable for electromagnetic shielding applications, especially in the direction parallel to the carbon fibers. The low-frequency voltage fluctuations observed in these materials are of the 1/fα, and the noise intensity is proportional to the square of the voltage. The characteristics of the investigated materials show an instability in the temperature range from 307 K to 332 K. This effect is followed by an increase in resistivity and noise intensity, but it does not change the character of the noise, and this instability vanishes after a few repeated heating and cooling cycles.

Large-Scale Fabrication of Tunable Sandwich-Structured Silver Nanowires and Aramid Nanofiber Films for Exceptional Electromagnetic Interference (EMI) Shielding

“…The thickness of EMI shielding materials is positively correlated with their shielding properties, making the improvement of an EMI shielding film’s efficiency a key focus in research [ 16 , 17 , 18 , 19 ]. In order to address this issue, researchers have conducted a diverse range of investigations, primarily focusing on the utilization of multi-layer structures, “brick-and-mortar” structures, aerogel structures, asymmetric structures, sandwich structures and other related approaches [ 20 , 21 , 22 ].…”