On the Dyes

Dyes are either ionic or very polar, the ones we used are no exception, except for Indigo, used to dye Denim, which is not very polar, nor does it dye fabrics with very strong colors.

Mordants

Fabrics ar often put into an aqeous solution containing metal ions, these ions help to increase the polarity of the fabric allowing it to hold more dye. These solutions with metal ions are called mordants. If you look at the bottom of the page you can see our dyed fabric strips. The methel Orange dyed significantly better on mordanted cloth.

On the Fabrics

Acetate, Arnel, Viscose and cotton

These four fabrics all have similar structures. They form an intricate laticework with few polar sites. These fabrics did not hold dye at all well due to their lack of polar sites to bond with.

Self-extinguishing fiber (SEF), Creslan 61, and Dralon

These three fabrics are made up of C-H bonds which are non-polar. They did not bond with Methel Orange very well, but when put in a mordant of FeSo4 it worked much better. The metal ions managed to connect the dye to the fabric. The Nitrogens have one pair of unshared electrons each. These fabrics held the Malachite Green very well.

Dacron 54 and Dacron 64

Dacron 64 took in the green dye well and did alright with the Indigo, but it didn't hold the Orange very well and Dacron 54 didn't hold anything at all very well. I don't know what the difference between them is, but aparently it makes one of them better for dyeing. Dacron 64 must have more polar sites. The only opportunities for bonding in the fabrics seems to be with the unshared electrons of oxygens, there are not many such places.

Nylon

Nylon is mostly made up of non-polar H-C bonds, but it does have some polar bond between Nitrogen and Hydrogen and Carbon and Oxygen. Despite these polar places I am suprised how well it held color. The prevelance of non-polar bonds makes this rather strange.

Polypropylene

Polypropylene is formed from Carbons and Hydrogens, the C-H bond is nonpolar therefor there are no polar sites for dyes to attach to. Needless to say this fabric didn't get very colorful.

Silk and Wool

Silk and wool are essentialy made up of protiens which have many polar sites. This gives the dyes many places to hook onto, and makes these fabrics very good at holding dye. These two fabrics showed the brightest color of all our fabrics.

#1 The Front Page

#2 The Procedure

#3 The Experiment