The Study of Desalination for Disrupted Wall Paintings at Cave 98 of Mogao Grottoes

Disruption means that the soluble salts in the plaster layer of a wall painting changes their form from dissolved to crystallized salts, and vice versa, with the changes of humidity in the surrounding environment. This change of forms creates an impact of swelling and shrinking in the plaster layer. This repeated impact damages the plaster layer and causes it to become loose and leads to deterioration. The only method to treat this deterioration caused by disruption of salts is to apply a combined method of reinforcement and desalination. The subject of this paper is the disruption of the wall paintings at Cave 98 of Mogao grottoes in China, in which synthetic material of high water and salt absorption, known as starch grafted acrylamide, is used as a desalination material applied on tissue of high water absorption to reinforce the disrupted wall paintings, to decrease the salts of the wall paintings, and to decrease the damage caused by the salts. This study tests the performance of desalination material and assessed the results in two different ways.