A quantitative study of the effect of ph on the dyeing process with juglone

الملخص EN

The use of natural dyes obtained from plants has been a well-known art for many thousands of years.

This ancient practice continued unchanged until the mid 19th century when synthetic dyes were invented.

Many people became aware about the hazards of chemical dyes.

Recently, many cosmetic companies all over the world launched a range of hair coloring products containing natural dyes.

But this practice needs scientific optimization and worth intensive research.

One of these natural dyes is walnut extract which contains an effective coloring agent, juglone, a brown dye which adheres directly to the keratin fibers without a fixing agent.

The objective of this work is to study the effect of pH on the dyeing process with walnut-extract-related material (juglone).

Bleached wool felts have been dyed with juglone, the principal coloring agent of walnut.

A dissolution technique that could evaluate uptake and substantivity was adopted.

The mass of juglone removed from the wool was assessed from the reflectance readings, related to changes in Lab values of dyed felts which were recorded before and after extraction.

A theory linking dyeing performance to electrolytic dissociation of juglone and keratin protonation was developed from the results.