Old maps and the effectiveness of chitosan as antimicrobial agent

Abstract

In the case of tangible cultural heritage items made of natural fibres, biodegradation due to microorganisms can lead over time to undesirable deterioration, including physical, mechanical and chemical damage as well as aesthetic alteration of materials. In this study, the antifungal activity tests were performed on 3 old maps (on silk, on canvas and on paper) using the AATCC 30-2004 test method. Map samples were immersed in a chitosan solution (10 g/l) and evaluated using Scanning Electron Microscopy (SEM) with a Field Emission Scanning Electron Microscope (ULTRA 55, ZEISS). The process showed that, due to its antimicrobial effect, chitosan treatment is effective for removing external agents and microorganisms present on fibre surfaces. The technique is simple, efficient and the results indicated that chitosan can be transformed into a very good and cheap antimicrobial solution for the conservation and preservation of heritage objects.