Improving the microwave absorption in Ni-coated fabrics by saccharin addition in plating bath

Polyester fabrics are coated uniformly by nickel thin film nanostructure with 200 nm thickness by electroless plating method. This study investigates the effect of saccharin as an additive in plating solution, on the morphology, grain size, crystallinity, surface resistivity, and magnetic properties of the coated fabrics which influences the microwave shielding strongly. The morphology changes from spheroid to blade shape with an average grain size of 85 +/- 10 nm and the surface resistivity reached to its lowest value in 5 g l(-1) saccharin concentration. It has been seen that the crystallinity is modified and the magnetic behavior becomes softer in the presence of the additive. The measurements on microwave shielding effect in 8.2-18 GHz frequency range exhibited 98-90 and 96-85% effective transmission loss (without and with the additive) by flexible and lightweight Ni-coated fabrics. The shielding effect becomes dominated by the absorption mechanism as higher eddy current loss, higher magnetic hysteresis loss, and shape anisotropy along blade shape nanostructure while saccharin is added to plating bath.