Insights into electrolytic stabilization with weak polarization as treatment for archaeological copper objects

Abstract

Immersion of corroded copper artefacts in dilute sodium sesquicarbonate solution is a well-recognized stabilization technique-especially in the conservation of objects recovered from marine environments and therefore saturated with chlorides. Here we describe three linked experiments performed to investigate a variation on this treatment, involving the application of a low potential to the artefact in order to drive the chloride extraction process. This includes a new spectroelectrochemical approach which allows 2-D pseudorandom X-ray reflection diffraction patterns to be obtained without interrupting the reaction in solution. Experiments were carried out on synthetically produced chloride layers on copper (nantokite and atacamite). We show that a thick chloride layer is, in general, replaced by a thin cuprite layer through a mechanism which involves detachment of the chloride crystallites from the surface prior to dissolution.

In‐situ spectroelectrochemical study of the growth process of a lead decanoate coating as corrosion inhibitor for lead surfaces

“…This type of information is only available from an image as opposed to a one-dimensional diffraction spectrum. [13] Fig. 1(d) shows part of the spectrum extracted from the image after reprojection and integration.…”

Towards a new method for coating heritage lead

“…The remaining six scans observed the drying and coating formation, although some evaporation occurred between the first four scans. SR-XRD patterns from (i) and (ii) above were extracted and analysed using the esaProject software [17] which can produce images such as those shown in Figure 2.…”

Tracking the progression of bronze disease – A synchrotron X-ray diffraction study of nantokite hydrolysis

“…When the sequence had finished, the coupon was soaked in water for 3 h then a further pattern (1-s exposure) captured a final image of the coupon. Data were batch processed using the code esaProject (Ó EVA Surface Analysis 2006-2012) [15] to integrate 1-D diffraction patterns from the rings, normalize them to the beam monitor, remove the background, and extract trends.…”