posted on 2021-10-26, 19:36authored byElena Possenti, Chiara Colombo, Marco Realini, Cai Li Song, Sergei G. Kazarian
In
this study, the novel application of ATR–FTIR spectroscopy
and macro ATR–FTIR spectroscopic imaging overcame an analytical
challenge in conservation science: the time-resolved, chemical, and
spatial investigation of the reaction of inorganic treatments for
stone conservation (ammonium oxalate, AmOx; ammonium phosphate, DAP)
occurring in water-based solutions. The aim was to (1) assess the
composition and localization of reaction products and their phase
variation during the reaction in real time and directly in an aqueous
environment and (2) investigate the reaction of AmOx and DAP with
calcite and the transformations induced to the substrate with a time-resolved
approach. The new analytical results showed that for both treatments,
the formation of new crystalline phases initiated at the early stages
of the reaction. Their composition changed during the treatment and
led to more stable phases. The reactivity of the stone substrate to
the treatments varied as a function of the stone material features,
such as the specific surface area. A clear influence of post-treatment
rinsing on the final composition of reaction phases was observed.
Above all, our research demonstrates the actual feasibility, practicality,
and high potential of an advanced ATR–FTIR spectroscopic approach
to investigate the behavior of conservation treatments and provided
new analytical tools to address the choices of conservation in pilot
worksites. Lastly, this study opens novel analytical perspectives
based on the new possible applications of ATR–FTIR spectroscopic
imaging in the field of conservation science, materials science, and
analytical chemistry.