The Study Of Conductive Function Textiles Prepared Using Hydrazine Reduction Electroless Plating Method

Nickel is a ferromagnetic material, and has strong catalytic effect on reduction reaction of most reducing agent. However, using sodium hypophosphite, sodium borohydride and alkyl amine boranes as reducing agent, chemical plating coating are alloy coating and the performance of coating has greatly changed. For example, for magnetic metals such as nickel, iron, cobalt, due to the introduction of the impurities make its original magnetic can be weakened or even disappeared, its electrical conductivity also fell sharply at the same time. Using hydrazine as reducing agent can get pure metal coating and keep all the original performance of this kind of metal. Meanwhile, in alkaline conditions, hydrazine has strong reducibility and its reduction products were gas and wa-ter. As a result, no harmful substances produced caused the decline in the use performance of the plating solution. Because of the strong catalytic activity of the metal nickel itself, nickel salt as activator instead of metallic palladium so as to realize the palladium-free activation.As chitosan has many excellent properties, such as a strong metal ion complexing ability, large adsorption capacity, good film-forming property etc, the surface of polyamide fabric con-tains a large amount of surface functional groups after modified with it. Then, respectively com-pleting the adsorption in nickel sulfate solution and activation process in reducing agent solution. Finally, electroless plating. This paper made a systemic discussion on the pretreatment conditions of polyamide fabric pretreated by CTS, then we work out the proper pretreatment conditions as follows: the concentration of chitosan18g/L, the concentration of nickel sulfate50g/L, the adsorp-tion time55min. The surface morphology and elements of the fabric at before and after pretreat-ment were characterized by means of FE-SEM and EDS. The results showed that a uniform thin chitosan film formed on the surface of the fiber, and the surface of the fabric after activation formed a large number of scattered distribution nickel particles.Secondly, the deposition metal nickel on the surface of nylon fabric using nickel activation process and the hydrazine reduction chemical plating nickel reaction system with ammonia as complexing agent. The optimum process conditions obtained through orthogonal and single-factor experiments were as follows:the concentration of nickel acetate48g/L, the concentration of hy-drazine20g/L, the concentration of ammonium sulfate7g/L, pH=8.5, the temperature of electro- less nickel plating77℃, the time of electroless nickel plating110min. FE-SEM, EDS, XRD and TG were used to characterize performances of nickel-plated fabrics. The results showed that com-pact and smooth nickel coating were obtained by using the above method and does not contain other impurities. The grain size was12.20nm, with(Ⅲ) crystal plane prefered orientation obvi-ously. The saturation magnetization of nickel coating was331.40emu/g. During300kHz-3000MHz, the electromagnetic interference shielding effectiveness values of nickel coating can reach more than50dB.Finally, the deposition metal copper on the surface of nylon fabric using nickel activation process and the hydrazine reduction chemical plating copper reaction system with sodium citrate as complexing agent. The optimum process conditions obtained through orthogonal and sin-gle-factor experiments were as follows:the concentration of nickel sulfate lOg/L, the concentra-tion of copper sulfate35g/L, the concentration of hydrazine27g/L, the concentration of ammoni-um sulfate lOg/L, the concentration of sodium citrate13g/L, pH=8.5, the concentration of boric acid17g/L, the temperature of electroless copper plating65℃, the time of electroless copper plat-ing2h. Properties of copper-plated fabrics were characterized by FE-SEM, EDS, and XRD. The results showed that compact and smooth copper coating were obtained by using the above method and does not contain other impurities. The grain size was27.1nm, with(Ⅲ) crystal plane pref-ered orientation obviously. During300kHz-3000MHz, the electromagnetic interference shielding effectiveness values of copper coating can reach more than50dB.