Question

what kind of bonds are there in a dye?

Answer 1

An attraction between the atoms which allows the formation of a chemical substance (compound) which contains two or more atoms is called as a chemical bond. A bond is a cause of the forces of attraction of opposite charges (i.e negative or positive) either between nucleus or electrons or formed as a result of dipole interactions.

In dyes, there are three kinds of dyeing mechanisms listed as follows:

1. Specific bond between the fibre and the dye which owes to hydrogen bond, covalent bond or other direct bonds.

2. Non-Specific bonds between the fibre and the dye which owes to vanderwaal's forces or ion-exchange bonds.

3. Absence of any interaction: This might be due to the dye may not be soluble in the fibre.

A short summary of types of bond is given below for the better understanding:

1. Vanderwaal' forces: Very weak interactions between the nucleus of an atom and electron of another atom is always present in close proximity. Although these forcs of interaction are very weak, but altogether they have a good strength to be the forces between dyes and fibres. For instance, disprse dyes are held by polyester fibres by Van de waal's forces.

Hydrogen bonding: The forces of attraction are weak and are set up between certain atoms in a dye molecule and the fibre, one of these atoms is the hydrogen atom and hence the term Hydrogen Bonding.

3. Covalent bond: These are the bonds which are resulting from very strong chemical forces and which cannot be readily broken apart except in some severe conditions. For example, combination of reactive dye-stuff with cellulose fibres wherein the hydroxyl group in cellulose is bonded covalently to the reactive dye.