Study Of Electroless Silver Plating On Pan Fiber With Chelating Agent Of Aptes/Mptes

With the development of the synthetic fiber production technology, a variety of modified polyacrylonitrile fiber which has high-shrinkage, anti-pill, hydrophilic, flame retardant propertiesand so on) come out. The application filed of the polyacrylonitrile (RAN) liber is enlarged when PAN fiber coated with metals as the properties of which have high valuable performance, conductivity, electromagnetic shielding and antibacterial characterics are improved a lot.It have better development prospect, though little research has been reported on this.The main purpose of this study is modifying PAN fiber by silane coupling agents APTES and MPTES, PAN fiber was provided with multi-chelating-group on it. Through the chelating effect, it can be directly used to eletroless silver plating without roughening, sensitization and activation. The influence of modification conditions (concentration, temperature and time) on eletroless silver plating were studied in details. The optimum modified conditions of the PAN fiber was drawn through orthogonal experiment and single-factor experiments, the results were as follows: concentration of APTES80g/L, treatment temperature85℃, treatment time2.5h; concentration of MPTES60g/L, at room temperature treated2.5h. The original, modified and silver-coated PAN fiber were characterized by FTIR, SEM, XRD and EDX respectively.The results indicated that:relevant chelat group was generated after the modification of the PAN fiber, the silver-coated fiber obtained by this method has a uniform and compact layer as well as good conductivity. The resistance value of the silver-coated PAN fiber is about2Ω/cm while the corrosion resistance has been improved.The deposition velocity of the silver particle in the traditional electroless plating was improved by increasing the temperature, the concentration of the silver ions and reductant. However, with the increasing of the temperature and the concentration of the silver ions and reductant, plating solution became more unstable of the. What’s more, the dimensions of the silver particle increased and the compactness of the silver layer was affected. In order to stabilize the plating solution, purify the silver layer and improve quality of the silver coating, the effect of rare earth (RE) on silver electroless plating wasd added into the plating solution. When RE La was applied, the optimum electroless conditions of the PAN fiber were:concentration of lanthanum nitrate0.01g/L, concentration of silver nitrate35g/L, concentration of glucose70g/L, temperature55℃.When RE Ce was applied to the silver electroless plating of the modified PAN fiber, the optimum electroless conditions of the PAN fiber was concentration of cerous nitrate0.005g/L, concentration of silver nitrate25g/L, concentration of glucose80g/L, temperature50℃.The grain size of the silver particle, the crystal structure and surface morphology of the silver-coated fiber film, and the electrochemical property of the plating bath were characterized by nano particle sizer(Nano-ZS), X-ray diffraction(XRD), scanning electron microscopy(SEM), cathodic polarization curves, and cyclic voltammogram(CV) respectively. The effect of RE on the speed of plating, the quality of the silver film and electrochemical property of the plating bath were analyzed. The results showed that the speed of metallic ions depositing, quality of the silver-coated fiber film were improved in varying degree while appropriate amount of RE was doped in the plating bath. With appropriate amount of RE in the plating bath, the polarization degree, the redox current peak and the speed of metallic ion depositing were all increased. The corrosion resistance of the silver-coated PAN fiber which obtained when adding RE was greatly improved.