Nanorestore Paper® dispersions are used for the pH control and deacidification of cellulose-based artifacts. The use of nanoparticles grants good penetration into the porous substrate, quick neutralization of the pH and the formation of an alkline buffer. These systems represent an alternative to methods that use micron-sized
particles and precursors of hydroxides (or carbonates). The use of organic
solvents makes Nanorestore Paper® formulations compatible with water-sensitive substrates.
When are they used?
Acidity affects several types of artworks, leading to their weakening. For instance, cellulose-based artifacts, such as paper, wood and canvas exhibit loss of mechanical properties due to acid hydrolysis of cellulose. It is therefore necessary to counteract acidity through the neutralization of the pH and the application of an alkaline buffer on the endangered material.
How do they work?
The particles adhere to the cellulose fibers, and neutralize acidity on site. The excess of particles reacts with CO2
in the atmosphere, turning into carbonate. It has been shown that a neutral pH also inhibits the oxidation of cellulose by iron and copper ions, as those present in the classic metal-gall inks.
How are they used?
The dispersions of nanoparticles are typically applied either by brushing, dripping or spraying over the artifact's surface, or by immersion of the artifact into the dispersion. When hydroxides are used, full carbonation takes place in 2-3 weeks, also depending on the hydrothermal conditions.
For further information, please refer to the technical sheet
1. Piero Baglioni and David Chelazzi, Nanoscience for the Conservation of Works of Art
, Royal Society of Chemistry, 2013
2. Piero Baglioni, David Chelazzi and Rodorico Giorgi, Nanotechnologies in the Conservation of Cultural Heritage: A Compendium of Materials and Techniques
, Springer, 2014