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D: How did your research come about?

Druzik: “At the time I joined the Getty, several institutions were doing research on paper conservation. The National Archives was the first to measure pollutants in archival settings. Since then the Canadian Conservation Institute has also done work that proved the negative effects of acetic acid on paper. The Image Permanence Institute did likewise on photographs. This was becoming a pressing issue. Our goal at the Getty is to create a pristine environment for artifacts, so I initiated a study on pollutant absorbents.”


D: What was the objective of your research? What absorbents and gases did you use and why?

Druzik: “My goal was to identify materials that would be most effective at absorbing and retaining acetic acid, and that would be suitable for use in preserving artifacts. I looked at about 18 different materials, including activated carbon, clays, calcium carbonate and several zeolites, which are a common natural product. I was intrigued by zeolites as they are known for their very effective and high-capacity adsorption and are used extensively in other fields.

“My research consisted of exposing the various adsorbent materials to acetic acid gas to determine adsorption capacity, then subjecting the “saturated” materials to a variety of tests to determine how well the gas was held. These tests included heat and exposure to other materials that might possibly displace the acetic acid inside the adsorbent like water vapor and hydrocarbon solvents. I wanted to find the material or materials that would hold the acetic acid, even under the most adverse conditions.”

D: What were the results of the research?

Druzik: “The activated carbon and one of the zeolites—called SPZ, this is the zeolite found in the Artcare technology—performed significantly better than the other physical adsorbents. Although activated carbon has better retention of acetic acid generally, it is, unfortunately, black and sooty, making it unsuitable for most conservation treatments. The SPZ, on the other hand, is white and clean, and performed extremely well. I haven’t yet published the full results, but I can tell you that the SPZ held the adsorbed acetic acid much more tenaciously than carbon during influxes of high humidity. In addition, my preliminary findings seem to indicate that a combination of the SPZ zeolite and calcium carbonate would provide a truly synergistic adsorptive and reactive framework.”

D: What do these results mean to conservators and picture framers?

Druzik: “Based on its adsorption and retention of acetic acid—which can be assumed to inhibit cellulose deterioration—the SPZ zeolite, incorporated in Artcare MicroChamber technology, is a very viable material for preventive conservation applications.”

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