Effect of morphology and content of Ni nanoparticles on electromagnetic shielding coatings with salt resistance and heating performance.

Ni/CNTs shielding coatings are obtained on the surface of polymethylmethacrylate (PMMA) by scraping and electroless plating. The effects of pH, temperature and electroless plating time on the structure and performance of the coating are studied through orthogonal experiments, which provide guidance for the optimization of the quality of Ni coatings in the production process. The relationship between the surface morphology attributed to the Ni particles on carbon nanotubes (CNTs) and the mechanism of electromagnetic shielding performance is discussed in depth. The mechanism of electromagnetic shielding depends on the content of Ni nanoparticles. When the content of nickel atoms on the surface is large, the reflection loss is dominant. At this time, a uniform and dense nickel coating with a scale-like structure can be obtained. The total shielding efficiency (SE_T) value of the corresponding Ni/CNTs coating with good salt resistance and a certain Joule heating performance can reach 40.9 dB. In contrast, when the content is small, the absorption loss is dominant. [ABSTRACT FROM AUTHOR]