抄録
In the present study, removal of rust stain from silk and cotton fabrics using thioglycolic acid(TGA)that has reducing and chelating properties, was examined in supercritical carbon dioxide(scCO2). The scCO2 especially including co-solvent was expected to act as a medium carrying the TGA into and TGA-Fe complex out from the fabrics without damaging them. The rust artificially prepared on cotton and silk woven fabrics were significantly extracted by the treatment with TGA in water and partially in methanol, though replace with scCO2 resulted no cleaning. Addition of co-solvent such water and ethyl acetate in scCO2 made the fabric white by removing rust. However reduced iron was re-oxidized and the fabric was colored in brown by this ‘batch method’. Therefore, the fabric was washed in a mixed fluid of methanol and carbon dioxide after ‘batch method’. This method was called ‘batch/post-washing method’, which led to reduction and no re-oxidation.
