Enzymatic Removal of the Oily Dirt from a Coptic Tunic using the Enzyme Lipase

Harby Ezzeldeen Ahmed, Stavros S Gremos, Fragiskos N Kolisis

Abstract


This article presents an extensive study on the use of the enzyme lipase to remove the oily dirt from a child’s Tunic dated to the Coptic period. Furthermore, it presents interesting results about the effect of the enzymatic treatment on the mechanical and optical parameters of Linen using SEM, FTIR, XRD, CIE-Lab values and ASTM method D5035. To start conservation procedure the restorers in the museum had previously used different solvent mixtures to remove the oily dirt from the Tunic, but the oily dirt showed high resistance, therefore a new suggestion of a different approach should came to the treatment plan. Lipase is considered as nontoxic and is less aggressive alternative compared to highly polar organic solvents and/or strong alkaline mixtures. The study was undertaken using Linen textiles in order to identify the optimum condition for the use of the enzyme, in relation with the time, the enzymes concentration and the temperature. The samples were immersed with Olive Oil. Then a process of artificial thermal ageing was applied to the samples for different periods of time. After that the enzyme was applied at different concentrations for different time periods. Finally, the removal of the enzyme residues from the textiles after the treatment was studied.

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