The Getty Conservation Institute (GCI), working with other institutions, has engaged in extensive research into the permanence and application of conservation materials. This research has increased understanding of the properties of materials under treatment, as well as advanced knowledge of the chemistry and physics of the agents and processes used in treatment.

In collaboration with the Carnegie Mellon Institute, scientists evaluated cellulose ethers and certain water-soluble synthetic polymers as coatings for conservation application. Previously, no systematic study of the permanence or durability of cellulose ethers had been conducted. In this project, seven classes of cellulose ethers were evaluated in terms of their thermal, photochemical, and hydrolytic stability. The testing results provided a relative ranking of these materials in terms of their potential durability in conservation applications.

The consolidation of limestones and marbles in museums is normally accomplished with mixtures of acrylic polymers and alkoxysilanes that aid in the bonding of loose grains of stone, and provide surfaces compatible with other adhesives. A review of research in the development of stone consolidation systems led the GCI to collaborate with the Metropolitan Museum of Art to study the chemistry of several stone consolidants. Scientists conducted research on the role of various acrylic polymers in acrylic and alkoxysilane stone consolidants in a project designed to reveal interactions and to discover possible beneficial mechanical properties that might accrue from such interactions.

Parylene is a vapor-deposited, colorless, transparent polymer used in industry to coat microcircuitry and metals to prevent corrosion. The plastic film is water repellant but permeable to water vapour. In collaboration with the Royal British Columbia Museum, the GCI investigated the effectiveness of vapor-deposited parylene polymer treatments for ethnographic and museum artifacts. Findings suggested various adverse effects of the treatment. [2.7] Other research conducted on parylene evaluated its use as a possible surface coating to protect daguerreotypes from corrosion. In further research with parylene-C, GCI scientists studied the accelerated aging of modern, coated silk. Factors affecting the preservation of objects made from silk were reviewed, with particular reference to effects of coating both structurally strong modern silk and comparatively weak historic silk.

Although solvent-borne resins, such as acrylics and solvent-borne alkyds, set a standard of performance in certain applications, in many instances the fire hazard and toxicity of organic solvents mandate the use of water-borne resins. In collaboration with the Society for the Preservation of New England Antiquities, the GCI undertook research in the use of alkali-soluble acrylics in architectural conservation. The study addressed the advantages and limitations of ionically solubilized water-borne resins as consolidants for porous materials, mainly architectural plaster.

In collaboration with the Los Angeles County Museum of Art (LACMA) and the Getty Museum, the GCI evaluated the effects on sterling silver of various combinations of common generic abrasives and carrier fluids used to remove silver tarnish. Evaluation factors included the amount of silver removed, the ease of application and removal of abrasive, and the effect of cleaning time. The samples were characterized through visual and scanning electron microscopy, and the abrasives comparatively rated.

Experiments and practical experience with aqueous light bleaching have shown that when this technique is applied to rag papers it is effective and can produce aesthetically pleasing results. In another collaboration between LACMA and the GCI, research was undertaken to provide a detailed description of the effects of aqueous light bleaching on the changes in paper properties caused by subsequent aging. The effects of aqueous light bleaching were monitored by measurement of gross chemical alterations in paper components and of changes in the color and the strength of the sample papers.

Related Scientific Research Abstracts

  • 2.3 Evaluation of Cellulose Ethers and Certain Water-Soluble Synthetic Polymers as Coatings for Conservation Application
  • 2.6 The Role of Acrylic Polymers in Acrylic/Alkoxysilane Stone Consolidants and a Pilot Study on the Feasibility of Long-Chain Alkyl-Trialkoxysilanes and Mixed Alkoxytrialkoxysilanes as Stone Consolidants
  • 2.7 Evaluation of Parylene for Treatment of Ethnographic Objects
  • 2.8 Alkali-Soluble Acrylics in Architectural Conservation: Future Research Directions
  • 2.10 Use of Parylene as a Protective Coating
  • 2.11 Evaluation of Abrasive Materials for the Cleaning of Silver Objects
  • 2.13 Evaluation of Parylene-C for Conservation Application: I. Accelerated Aging of Modern, Coated Silk
  • 2.14 Aqueous Light Bleaching of Paper