Green Dyeing of Wool Fibers Using Vanadium

Abstract

The technique to dye fibers green by using plant dyes, traditionally pre-mordanted by iron acetate, should be considered from the viewpoint of deepness and light-fastness of the hue. We have therefore investigated the use of vanadium as an alternative mordanting material, as it represents a transition element that is in the same period as iron. Wool fibers were dyed using tetravalent vanadium solutions, with solutions of 5 ×10^-3 mol/L vanadyl sulfate found to produce a deep green color and light fastness with a natural plant dye yashabushi 50 % owf. Electron spin resonance spectrum of vanadium on the wool was identified as signal associated with complex of oxovanadium remained in wool. It was shown that the wool dyed green by vanadium has low irritation to skin and the vanadium is effective as the new mordant which could reduce environmental load．