43rd Annual Meeting – RATS Session, May 15, "Polymer Coating Removal Nanosystems for Finely Controlled Cleaning of Cultural Heritage" by Piero Baglioni

I was certainly glad that I woke up in time for the first Research & Technical Studies talk of Friday morning’s session, which was presented by keynote speaker Dr. Peiro Baglioni.  Dr. Baglioni is the Chair of Physical Chemistry at the University of Florence and CSGI (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase, or in English…Center for Colloids & Surface Science).
Dr. Baglioni discussed the systems that they have developed to clean synthetic coatings as well as dirt and grime from pictorial art surfaces.  He started by discussing the Florence Flood of 1966, showing images of some of the resulting damage to cultural heritage, and explaining how new methods of conservation really developed as a result of this catastrophic event.  Dr. Baglioni explained that his work has focused on searching for new scientific methods and materials for conservation treatment.
His talk then launched into a group of newly developed cleaning methods.  This includes nanoparticles, micelles & microemulsions, and containers (gels).  These systems can be used for cleaning dirt/grime from mural paintings and wood, as well as for polymer coating removal.  Dr. Baglioni even mentioned paper deacidification applications.  Some of this information can be found on the Nano for Art site and I would urge anyone interested to check this link out.  Dr. Baglioni has also co-edited a book titled Nanoscience for the Conservation of Works of Art.
Dr. Baglioni put forth the question – why not just use solvents for cleaning?  He explained that synthetic polymers have been popular for conservators since the 1960s, but can age poorly.  He showed examples of poorly aged polymer coatings at the Mexican Mayapan site.  Using traditional solvents and swabs in coating removal can cause the solubilized polymer to inadvertently be injected into cracks within the deteriorated art surface.  Alternately, using microemulsions not only keeps the cleaning material on the art surface, but also has the added benefit of being less toxic for the conservator.
3 types of cleaning gels were discussed: 1) PVA/Borax hydroxide gels, 2) Hydrogels, and 3) Organogels.  Dr. Baglioni explained that the PVA/Borax hydroxide gels could be used as a peeling gel, i.e. can be placed on a surface and then peeled off later.  The hydrogels could be a carrying system for various solvents and solutions.  They can also be cut into gel squares and even re-used.  Impressive visible light, UV light, and SEM photos of surfaces at various stages of cleaning showed how effective yet safe these cleaning gels can be.
Personally, I would love to try out some of Dr. Baglioni’s cleaning materials!  There are definitely applications for a wide range of art surfaces.  The cleaning materials are trademarked, but I believe they are available commercially (does anyone know where to purchase them?).  Dr. Baglioni has so much valuable information to share with the American conservation community.  I’m sure I’m not the only one that wished that his talk could have gone on a bit longer so that he could go into more detail.  It seems like this talk only covered the tip of the iceberg in regards to his research.  Excellent way to start out the RATS session!

43rd Annual Meeting – RATS Session, May 15, "New Inorganic Consolidants for the Restoration Market: Results From Nanomatch EU Project" by Adriana Bernardi

Dr. Adriana Bernardi was the presenter for this co-authored talk.  She is affiliated with Padua University, a senior researcher at CNR-ISAC (Institute of Atmospheric Sciences and Climate of the National Research Council of Italy), and head of the ISAC Unit of Padua.  First, Dr. Barnardi explained that 13 partners from 7 European countries were involved in the Nanomatch project.  This was a large-scale collaborative project with the aim of developing better consolidants for stone, wood, and glass artifacts.  Discussions of wall painting consolidation were included as well.  The developed consolidants had to be sustainable, react well with the substrate, and be safe to use.  This talk discussed the testing and results of several new consolidants.
For stone and wood the class of consolidants that Dr. Barnardi described were calcium alkoxides.  For glass, the consolidants were aluminum alkoxides (A18).  Dr. Bernardi talked about the strategy for developing these consolidants.  A mix of lab experimentation and field exposure was used in their development and testing.  Mock-ups were made of wall paintings, wood, glass, and stone artifacts for testing purposes.  Field tests were also done in several EU countries and Dr. Bernardi mentioned historical samples being tested as well.
The results of the Nanomatch Projcect were quite positive.  There was too much detailed information to include everything in this blog post, but here are some of the highlights:

  • Stone – developed consolidant had good workability and use, was comptablible with stone, and there was no color change.
  • Wall painting – good workability and ease of use, good aesthetic results but decreased concentration needed for some colors.
  • Wood – acid neutralization in alkoxide treated wood.  The consolidant acts as an alkaline supply.
  • Glass – consolidant A18 is highly compatible with glass (transparent, similar refractive index), good adhesion to glass, can penetrate cracks.

Dr. Bernardi showed videos during her presentation that demonstrated the use of the consolidants on stone, wood, and glass during Nanomatch training workshops.  In conclusion, the newly developed limestone, wall painting, and glass consolidants all seemed effective as consolidating materials, while the wood “consolidant” was more effective in acid neutralization.  If you’d like to know more about this project and the composition of the consolidants, visit the Nanomatch website for more information.
IMG_0758