Art restoration by FTIR microscopy? Of course! But let’s start at the beginning.
The world is full of wonderful art, monuments and buildings made from marble, limestone and other carbonatic materials. Think of the Taj Mahal in Agra, the Colosseum in Rome or the Washington monument in D.C.
While these materials are very sturdy and have withstood time and weather for hundreds of years, our modern industrialized environment increases the stress on these historic artifacts.
How is deterioration countered?
The problematic deterioration of carbonates is commonly treated using DAP (diammonium hydrogenphosphate (NH4)2HPO4) as a consolidant.
While the chemical’s reaction with defined minerals such as calcite is well understood, the treatment of complex materials like limestone and marble is quite complex and is in dire need for investigation to improve art restoration efforts.
That’s why recently, italian scientists took a closer look at the process of treating Carrara marble with DAP. For this they introduced a novel “ad-hoc multianalytical approach by combining high-resolution FTIR micro spectroscopy, XRD and synchrotron radiation in transmitting geometry.”
FTIR helped to protect history!
They were able to overcome the previously encountered analytical limitations and characterized the reaction taking place on the shell of the marble. A multitude of newly formed compounds take part in consolidating the material including the formation of heterogeneously distributed DCPD, which might act as a further sacrificial phase for the protection from environmental influences.
Read more in the full article
The µ-FTIR research was performed with a Bruker LUMOS FTIR microscope using its automated knife-edge apertures to measure structures close to the diffraction limit.
References: E. Possenti et al. Construction and Building Materials 2019, 195, 557–563.