Effect of silver plating time on the properties of conductive silicone rubber filled with silver-coated carbonyl nickel powder

This article investigates the effect of the silver plating time on the microwave shielding and mechanical properties of the conductive silicone rubber filled with silver-coated carbonyl nickel powder. The results show that the electromagnetic shielding effectiveness (SE) of the rubber with the silver-coated carbonyl nickel powder rises up to about twice that of the rubber with the carbonyl nickel powder and the elongation of the rubbers at break increases when the plating time reaches 40 min. The property improvement is related to the strengthening effects of the silver coating layer on the carbonyl nickel powder in the rubber. The silver coating layer builds a silver-silver conductive channel and a cooperative mechanism of the electromagnetic wave reflection and absorption. That is beneficial to increasing the SE of the rubber. In addition, the silver coating layer on the surface of the carbonyl nickel powder has a better combining ability with the rubber than the powder itself, which may play an important part in the increase of the elongation.