2.1.1. Wool
Wool fabric (plain weave and weight, 118 g/m2) was procured
commercially. Before being used, it was bleached with a solution
containing 25 mL L−1 hydrogen peroxide (110 vol.) and 1 mL L−l
ammonia (30%) at 55 ◦C for 60 min, keeping the material to liquor
ratio at 40:1. Then, the bleached material was neutralised with
formic acid solution then thoroughly washed with distilled water
and dried at room temperature during 48 h.