Conductive Filler With Silver Plating Of Non-metallic Oxides New Technology Research And Applications

The non-metallic powders that are coated with metal or metal alloy can be used as conductive fillers, conductive coatings, electromagnetic shielding materials, absorbing materials, and sheltered plane materials. Now their applications are widely, especially the Ag-coated glass fibres and hollow glass microspheres because of their small density, good conductivity, good stability to be made great attractive as conductive fillers. In this paper, we tried to get Ag-coated products by electroless silver plating on the glass fibres and hollow glass microspheres and by replacing the conventional PdCl₂ activator with AgNO₃ activator to reduce the overall cost of the coating process. The surface pretreatment and the process of electroless silver which affect the coatings have been discussed. The electric conductivities of Ag-coated materials were also tested.The surface pretreatment process is very important in electroless silver plating on the glass fibres.The influence factors of the weight loss by different ammonium fluodride ething and the conductivity after electroless silver plating were studied. It has been demonstrated the Ag-coated glass fibres have many advantages such as low resistivity and good adhesion by the ammonium fluoride solution ething with the low acid. The activator pretreatment of the glass fibres were studied by replacing the PdCl₂ activator with AgNO₃ activator, and date from this study have demonstrated we can get the low resistivity, dense and high quality compound materials by controlling PH of the activator solution.In addition, the influence factors of the process of electroless silver plating were studied and we obtained the optimum condition and the loadage.Otherwise, the surface pretreatment process is very important in electroless silver plating on hollow glass microspheres. Soaking the hollow glass microspheres in ethanol by ultrasonic wetting, and etching their surface with the adsorptive theory, and then testing the particle diameter of powders after etching by the particle-size analyzer and the compactresistance after Ag-coated the hollow glass microspheres, we found that properly controlling the PH of the ammonium fluoride solution can get the uniformed Ag-coatings. The activator concentration have great affect the coatings, the result displayed that by increasing AgNCh concentration, we can get more uniform and dense coating in thickness and more small compact resistance. The influence factors of electroless silver plating by adding to the surfactants were studied. We make use of different additives to disper, wet the solution. We concluded that by analyzing the particle-size and sintering that the good sinter is relate to the uniform coatings and we got the conductive filler with its compact resistance is 4X 10 3Q ? cm with the PVP as surfactant. In addition, During the process of electroless silver plating we will the dioxide bath is direct to add to [Ag(NH3)2]+ solution, and then dropping the silver-plating bath. The changed process can reduce the the procedure and get the uniforming coating and control the precent weight of Ag-coated.The compound materials are characterized by particle-size analyzer, X-ray diffraction analysis, energy dispersive, scanning electron microscopy and spectrum during and after the coating process. The result replayed that we can obtain the uniform and dense Ag-coating and do not reveal the presence of Sn, Cl on the surface, and the possible mechanism of electroless Ag-coating of compound materials utilizing AgNC>3 activator is suggested. In the end, some problems are put forward to be studied in future work.