article posted 08 Feb 2016
Teresa Palomar is Doctor in Chemistry from the Autonoma University
of Madrid, she has focused her research to the corrosion and conservation of inorganic
materials from cultural heritage, especially on glass and metal. Currently, she is making
a post-doc in the Centro do Vidro e da Cerâmica para as Artes (Lisbon, Portugal).
Effect of marine aerosols on the alteration of silicate glasses
Teresa Palomar1*, Anne Chabas2, David M. Bastidas3,
Daniel de la Fuente3, Aurelie Verney-Carron2
Stained glass windows are the historical glasses most affected by atmospheric degradation. Several works have
assessed the influence of pollution on degradation mechanisms, but the studies on the effect caused by marine
aerosols are very scarce, previous works have shown that the presence of neutral salts
(NaCl, KCl, CaCl2
, NaBr, Na2
dissolved in pure water lead to increase the corrosion rate of quartz and commercial glasses.
In this work is presented the study of the effect of saline aerosols on soda-lime, potash-lime and lead silicate
glass samples. NaCl aerosols were deposited over a first set of samples of silicate glasses in the CIME,
Chambre d'Interactions Matériaux-Environnement (LISA-UPEC, France), and afterwards they were
exposed during 38 days to different relative humidity (RH) conditions: 20% RH, 100% RH and variable
20-100% RH, at a constant temperature (20ºC). The second set of samples was exposed to the real marine
atmosphere of Cabo Vilano (Galicia, Spain) during three months. For comparative purposes, a 20th century
stained glass window from the Treasury Department Delegation of Málaga, in the south coast of Spain,
was also characterized. A set of analytical techniques to assess the physicochemical effects were used,
including optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy,
micro-Raman spectroscopy and small-angle X-ray diffraction.
Any alteration pathologies were observed on soda lime and lead silicate glasses exposed to simulated
conditions, whereas the potash lime silicate glass presented fissures and new crystalline phases over the
glasses including carbonates and sulphates. All the samples exposed in Cabo Vilano showed new crystalline
deposits over their surface, potash lime silicate presented also small fissures, indicating that this glass was
the least durable one. Similar deposits were observed in the 20th century stained glass window.
1 Depto. de Conservação e Restauro and Research Unit VICARTE-Vidro e Cerâmica para as Artes, Campus de Caparica, FCT-UNL, Quinta da Torre, 2829-516 Caparica, Portugal
2 Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Universités Paris-Est Créteil et Paris Diderot CNRS, 61 Avenue du Genéral de Gaulle, 94010, Créteil, Cedex, France
3 Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Superior de Investigaciones Científicas (CSIC), Ave. Gregorio del Amo 8, 28040 Madrid, Spain.