Silver coated textiles as multifunctional flexible materials

Among numerous active electrode materials, nowadays applied in capacitor devices, silver nanostructures represent promising electrodes for electrochemical capacitors, owing to their acceptable cost, large surface area and high electrical conductivity. In this work we investigate the electrochemical capacitance and electromagnetic interference shielding effect of two textile materials: polyester and cotton fabrics, coated with silver particles. The multifunctional materials were prepared in a manner that the fabrics were immersed into a silver complex solution and subsequently dried in the air and heated to induce silver deposition by annealing. This synthesis method does not apply electricity or any specific chemicals, and so the process is more economically acceptable for production of lightweight and flexible conductive materials. Characterization of the modified textiles and deposited silver particles were performed by scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), as well as with X-ray diffractometry (XRD). The capacitance and the amount of the electric charge stored were measured in the two electrolytes (KCl and NaOH), and for electrodes prepared by one, three, or five cycles of fabrics immersion in the silver solution. The capacitance was measured by cyclic voltammetry, while the capacity for electric charge storage was calculated from the recorded charge-discharge curves at the textile working electrodes. The signal attenuation was measured in the frequency range of 300–1000 MHz. After five cycles of metallization, the electromagnetic interference shielding (EMI SE) of silver coated cotton fabric in a lower examined range was 23.26 dB.