Fibre Treatment Technique by Using Laccaic Acid to Confer Functions of Capturing and Detecting Hapten Metal Ions upon Fibre Materials for the Prevention of Metal Allergy Symptoms

A novel treatment technique to confer functions of capturing and detecting hapten metal ions upon cotton fabric by using laccaic acid (LA) was studied for preventing metal allergy symptoms. Cotton fabrics were treated by the LA with using thionyl chloride and pyridine to give the functions. It was found that the LA-treated cotton fabrics adsorbed nickel ions and showed colour change from orange to deep purple by immersed in nickel chloride aqueous solution. The colour change was clear enough to be perceived by the naked eye. The LA-treated cotton fabric has sufficient adsorption capacity to capture Ni2+. It was evaluated that the LA molecule interacted with ten Ni2+ ions in aqueous solution. The colour change behaviour of the LA-treated cotton fabric by Ni2+ depended on pH. The LA-treated fabric adsorbing Ni and coloured was able to be regenerated repeatedly by washing with citric acid aqueous solution. The LA-treated fabric also detected Co2+, Cr3+, Cu2+, Zn2+ and Fe2+ ions by the colour change and the resulting colour depends upon the type of metal ions. The LA-treated fabric functioned for metal ions from metal alloys in artificial sweat solution.