The Preparation and Research on the Electromagnetic Shielding Effectiveness of T-ZnO@Ag/Silicone Rubber Composites

Abstract

This study first conducted surface modification of Ag-plated Tetrapod-like zinc oxide (T-ZnO) whiskers with the use of dopamine and prepared Ag-plated T-ZnO whiskers (T-ZnO@Ag) by means of chemical plating, in which AgNO3 solutions with different concentrations were used during the preparation. Micro-structures of the prepared T-ZnO@Ag powders were examined to evaluate the effect of AgNO3 concentration on Ag plating performance. Subsequently, conductive Si rubber samples were prepared, the T-ZnO@Ag powders were used as fillers, and the effectiveness of the related electromagnetic shielding was investigated in detail. The results showed that using AgNO3 solution with a concentration of 20 g/L, a continuous Ag coating-layer was observed on the surface of T-ZnO whiskers. It was evident that, when used as fillers, T-ZnO@Ag has a conductive threshold and when the mass fraction of the fillers exceeded 50 %, the T-ZnO@Ag whiskers that were uniformly dispersed in the matrix formed interconnected conductive paths. In this condition, the electromagnetic shielding effectiveness of the prepared T-ZnO@Ag/Si rubber composite reached up 90 dB.

Investigation on electromagnetic shielding and antiultraviolet radiation properties of ZnO@AgNWs/waterborne polyurethane composites

“…10,43 As electromagnetic waves enter the composite, numerous conductive flow networks composed of ZnO@AgNWs can decompose the electromagnetic wave energy, thus reducing the electromagnetic wave energy and enhancing its electromagnetic shielding performance. 44 By comparing the electromagnetic shielding mechanism of materials, EMI SE mechanism diagram of modified composite is drawn as shown in Figure 7. According to the previous analysis, the construction of ZnO@AgNWs composite conductive network makes the surface of composite form a thin conductive material network layer, which provides strong reflection and relatively large SE.…”

Large‐Scale Ultralight and Flexible Metal Foil/Polymer Sandwich Composites with Excellent Electromagnetic Interference Shielding

“…The presence of micropores further reduces its areal density, which is beneficial for its application as lightweight EMI shielding materials. Moreover, silicone rubber (SiR) possesses high flexibility compared with other polymer materials, [29,30] and it can be combined with Cuf to achieve the characteristics of low density and good flexibility of the composite materials. As far as we know, it is rarely reported that metal and polymer materials are macroscopically compounded through chemical bonds and mechanical interlocks.…”

Research on Electromagnetic Shielding Effectiveness of Multi-layered LZ91/Al Alloy Composite Materials by Asynchronous Accumulative Roll Bonding

“…According to the binary phase diagram of Mg-Li alloy [17], when the Li content is between 5.3 wt.% and 10.7 wt.%, the alloy shows a typical dual-phase structure, so it also has obvious advantages in electromagnetic shielding. When Al alloy is coated on Mg alloy, its plasticity and corrosion resistance can be improved through the complementary effects of various materials [18], and the addition of Al layer can improve the electrical conductivity of the material, which is similar to conductive coating materials [19]. Moreover, Al alloy and Mg alloy are both light metals, which will not deteriorate the shielding density of multilayered composite materials [20], in addition, the addition of the Al layer increases the number of alloy layers, strengthens the interface reflection, and is also conducive to electromagnetic shielding effectiveness.…”