TITLE:
The Influence of Gaseous Pollutants on Silver Artifacts Tarnishing
AUTHORS:
Yussri Salem
KEYWORDS:
Silver, Artifacts, Atmospheric Corrosion, Gaseous Pollutants
JOURNAL NAME:
Open Journal of Air Pollution,
Vol.6 No.4,
November
24,
2017
ABSTRACT: The present work investigated the effect of the common gaseous pollutants on silver artifacts corrosion. The study will be carried out on manufactured coupons of silver alloy (91 silver, 9 copper) which have chemical composition similar to ancient Egyptian silver artifacts. These coupons will be exposed to gaseous pollutants of each individual gas; such as Sulfur dioxide, Nitrogen dioxide, Carbon dioxide, Hydrogen sulfide and Chlorine. The exposure period will be four weeks in a climate chamber with gas concentration 10 PPM. After the test Examinations by SEM and PM were used to evaluate the effect of each gas and description the morphology of the corrosion layers. The results revealed that all gases reacted with the surface except carbon dioxide. The formed tarnishing layers varied in coverage and density rate. Corrosion products are analyzed by XRD and the results revealed Ag2S, AgCl, Ag2SO4 and Ag2O as corrosion products.