Studies On Preparation And Properties Of Ag/PANI/PET Composite

Electroless silver plating on fabric surface could impart conductivity, electromagnetic shielding and durable antibacterial properties to the material. The traditional electroless silver plating pretreatment process consists of etching-sensitizing-activation, where SnCl2 was used to reduce the activator PdCl2 in order to form metal catalytic center. The metal catalytic center is likely to reduce activation energy and initiate the metal deposition. However, this SnCl2 sensitizing method has many drawbacks such as low adhesion of gel layer to substrate, uneven coating and poor fastness. What’s more, SnCl2 was poisonous and harmful to environment. The noble metal, PdCl2, would be used after the sensitizing as a catalyst, increasing the cost of electroless plating.Among conductive polymers studies, polyaniline(PANI) with high conductivity, simple preparation and good stability was favored by the scientific community. Doped PANI can reduce many metal ions such as Ag(I), Au(III), Pd(II) and Rh(III). Based on its reduction property, this paper put forward a new pretreatment method using the in-situ polymerized PANI as reducing agent to in-situ reduce Ag(I) to Ag(0) species, which could act as catalytic seeds to initiate electroless plating. Amino groups in the in-situ polymerized PANI film could also adsorb and reduce silver ions, thereby improving the uniformity of the catalytic layer.In this paper, the optimal experimental parameters of polyaniline deposition on poly(ethylene terephthalate)(PET) fiber by in-situ polymerization were studied. The effects of several parameters, including aniline concentration, ammonium persulfate(APS) concentration, nitric acid concentration, bath ratio, on the uniform and reduction property of composite were discussed. The molecular structure, aggregation structure and condensed structure of polyaniline were characterized by Fourier Transform Infrared Spectroscopy(FTIR), scanning electron microscopy(SEM), X-ray diffraction(XRD), and Thermogravimetric(TG) analysis. The activated PANI /PET composite was characterized by X-ray photoelectron spectroscopy(XPS), where the effect of silver concentration to the sensitization results was also discussed.The optimum electroless silver plating conditions were discussed. The effects of silver nitrate concentration, reducing agent concentration, reaction temperature, additive concentration, auxiliary conditions(ultrasonic) on the fastness and conductivity of silver plated layer were investigated. The antibacterial properties and electromagnetic shielding effectiveness(SE) were also studied. The test results showed that the antibacterial property of the composite to Escherichia coli and Staphylococcus aureus was 100%, and the SE was 60-90 dB. The prepared material can be applied into the aerospace and military equipment electromagnetic shielding field.