AIC's 41st Annual Meeting

This presentation will offer an update on the continuing collaborative research project between The Dow Chemical Company, the Getty Conservation Institute and Tate, which aims towards development and evaluation of novel systems for the cleaning of acrylic paints. Early findings from this project were presented at AIC Los Angeles 2009 and AIC Milwaukee 2010.

One class of potentially useful formulations that was identified in the early phase of the project was (water-in-oil) microemulsions; these are thermodynamically stable preparations consisting typically of water, non-miscible (hydrocarbon) solvent, co-solvent and surfactant. Such preparations offered the possibility of exploiting the cleaning efficacy associated with aqueous systems but in a predominantly solvent environment. A series of trial microemulsion cleaning formulations prepared by Dow have been evaluated by Tate and conservators at a series of training workshops focused on the practice of cleaning acrylic painted surfaces, and those evaluations have contributed to further refinement of the formulations for better compliance with the performance criteria desired by conservators.
The presentation will report the progress of this ongoing research collaboration focusing in particular on the development of the microemulsion systems. Three classes of microemulsions have been developed to offer a range in cleaning power and formulation latitude. All three systems contain an aliphatic hydrocarbon continuous phase. The systems differ in the type of surfactant and presence/level of an alcohol co-solvent. The co-solvent is required with some systems to enable a stable microemulsion structure. Phase diagrams for these preparations will be presented which demonstrate the range of proportions of the respective ingredients at which stable microemulsion systems are maintained; these include preparations that are (hydrocarbon) solvent-rich and low in surfactant and water content. Observations will also be presented on the comparative performance of these cleaning systems from the point of view of the practicing conservator, including their application to a wider range of substrates.