Study On Electromagnetic Shielding Performance And Stability Of Electroless Silver-plated Nylon Fabric

With the rapid development of modern electronics industry,electronic products will produce a certain electromagnetic waves in the course of the operation.The electromagnetic wave will not only produce some electromagnetic interference to the surrounding electrical and electronic equipment,but also produce a certain degree of electromagnetic radiation hazards on the human body.Therefore,the development of materials with high electromagnetic shielding effectiveness has an important significance for inhibiting electromagnetic interference and electromagnetic radiation hazards.In this paper,the silver plating polyamide fabrics(SPPFs)were be fabricated by using in-situ reduction of polydopamine and electroless silver plating.Electromagnetic shielding effectiveness(EMSE)of SPPFs prepared under different process parameters were analyzed.Three factors which effect the electromagnetic shielding properties were explored,including different concentrations of silver nitrate solution and dopamine solution,silver increasemnet rate(SIR)and surface resistivity of SPPFs.The surface morphology,electrical conductivity and shielding effectiveness(SE)of SPPFs were characterized by thermal field emission scanning electron microscopy,new digital multimeter and vector network analyzer.The experimental results show that when the concentration of silver nitrate solution is 120 g/L and the concentration of dopamine solution is 4 g/L,the SE is the best and the SE value reaches 78.96 ± 7.64 dB.Under the condition of stable SPPFs,the EMSE gradually increases with the increasement of SIR.When the SIR reaches more than 90%,the EMSE tends to be gentle with the SE value above 75 dB.When the surface resistivity deviation of SPPFs is less than 15%,the SE is enhanced with the decrease of surface resistivity.When the surface resistivity is less than 0.1 ?·cm,the SE is best and the SE value is above 70 dB,the attenuation is almost 100%.At the same time,it is found that the stability and uniformity of the SPPFs is also an important factor that affects the EMSE.The stability of the SPPFs is explored through the heat treatment and the ultrasonic treatment of the reduction reaction in the experiment.The experimental results show that the heat treatment of the reduction reaction improves the SIR,but the silver plating solution is in an unstable state,and the uniformity of the SPPFs is also decreased.Therefore,the heat treatment of the reduction reaction plays a negative role in the stability of the electroless silver plating.Using ultrasonic treatment in the reduction reaction of electroless silver plating,it can make the silver coating become more dense,more smooth,and improve the quality of silver coating.What's more,it can increase the amount of silver nanoparticles deposited in the coating,the overall performances of the silver coating improved significantly.SPPFs were widely utilized as anti-static fabrics garments,electromagnetic pro-tective garments and antibacterial fabrics due to their excellent electroconductibility and biocompatibility.At the same time,it can be also used in the field of smart gar-ments,electrode materials,flexible sensors,etc.