In an advance that could help conservationists restore paintings to their original glory, chemists have developed a cleaning product that switches from a free-flowing liquid to a viscous gel.
The researchers tested the material on a 14th-century painting from the National Gallery in Siena, Italy. Layers of resin applied after the painting's completion had, over the centuries, dulled the artwork's color. The gel brightened the test spot on the painting, and analyses of the gel after its use showed that none of the pigments had been removed from the original paint layer. The researchers describe their product in the Sept. 28 Langmuir.
The so-called rheoreversible gel consists of a cleaning solvent mixed with a polymer called polyallylamine. Initially, the polymer was in a liquid form. However, when researchers bubbled carbon dioxide through it, the polymer chains linked up.