摘要
The mechanism of tarnish caused by exposure to light and Na_2S solution treatment on silver-electroplated deposit and the antitarnish effects of various antitarnish agents have been investigated in this paper. The results showed that 1-phenyl-5-mercaptotetrazole (PMTA) has excellent antitarnish effect for UV light and H_2S tests.The studies of XPS and AES and UV absorption spectra showed that PMTA can absorb effectively UV light and form a dense surface film which can prevent effectively the reactions between silver deposit with corrosive media.Antitarnish surface film could be composed of a polynuclear coordination polymeric compound with structure unit approximate to [Ag_3(PMTA)]. according to the depth dependence of percent component (C%) and sputtering time.
The mechanism of tarnish caused by exposure to light and Na<sub>2</sub>S solution treatment on silver-electroplated deposit and the antitarnish effects of various antitarnish agents have been investigated in this paper. The results showed that 1-phenyl-5-mercaptotetrazole （PMTA） has excellent antitarnish effect for UV light and H<sub>2</sub>S tests.The studies of XPS and AES and UV absorption spectra showed that PMTA can absorb effectively UV light and form a dense surface film which can prevent effectively the reactions between silver deposit with corrosive media.Antitarnish surface film could be composed of a polynuclear coordination polymeric compound with structure unit approximate to [Ag<sub>3</sub>（PMTA）]. according to the depth dependence of percent component （C%） and sputtering time.
