Degradation of Glass Artifacts: Application of Modern Surface Analytical Techniques

摘要

Adetailed understanding of the stability of glassesntoward liquid or atmospheric attack is of consider-nable importance for preserving numerous objects of ourncultural heritage. Glasses produced in the ancient peri-nods (Egyptian, Greek, or Roman glasses), as well as mod-nern glass, can be classified as soda lime silica glasses.nIn contrast, potash was used as a flux in medieval North-nern Europe for the production of window panes fornchurches and cathedrals. The particular chemical compo-nsition of these potash lime silica glasses (low in silicanand rich in alkali and alkaline earth components), in com-nbination with increased levels of acidifying gases (such asnSO2,CO2,NOx,orO3) and airborne particulate matter inntoday’s urban or industrial atmospheres, has resulted innsevere degradation of important cultural relics, particularly over the last century.nRapid developments in the fields of microelectronics and computer sciences, however, have contributed to the develop-nment of a variety of nondestructive, surface analytical techniques for the scientific investigation and material characteriza-ntion of these unique and valuable objects. These methods include scanning electron microscopy in combination with energy-nor wavelength-dispersive spectrometry (SEM/EDX or SEM/WDX), secondary ion mass spectrometry (SIMS), and atomic forcenmicroscopy (AFM). In this Account, we address glass analysis and weathering mechanisms, exploring the possibilities (andnlimitations) of modern analytical techniques.