Intermolecular forces between dyes and fabric:
Table of Contents
Introduction:
Dyeing is usually done by transferring the dye from the solution to the inner surface of the fiber and by Exploitation the fiber surface. As a result, the dye molecules move from the outside of the solution to the fiber which is called Exhaustion. It is also called fiber substratum.
The dyes that absorb the dye on their own when they come in contact with the fiber are called substantivity for the fiber. This substantivity is through the operation of a variety of attractive forces between die molecules and fiber molecules. There are different types of attractive force, the presence of which can be noticed during dye fiber binding.
1) Electrostatic force
2) Vander Waals force
3) Hydrogen bond or H-bond
4) Covalent bond
1) Intermolecular forces between dyes and fabric-Electrostatic force:
Such a force of attraction is usually caused by the opposite of the electric charge between the dye and the fiber. They are not affected by the non-ionic environment. But the ionic group of fibers is more influenced by the ions of the external environment. The dye can be an-ionic, non-ionic, and cationic. In the case of wool dyeing in acidic conditions, the wool fiber becomes positively (+ve) charged and attracts and absorbs through the (–ve) charged dye an-ionic electrostatic ball.
2) Intermolecular forces between dyes and fabric-Vander Waals force:
Vander Wall Force is of two types.
a) Puller vendor wall force: Vander action occurs for the puller properties of both fiber and dye.
b) Non-puller Vander Wall Force: This force acts on the force due to the induction of a puller.
3) Hydrogen bond or H-bond:
In some cases, the presence of water can cause an H-bond between the fiber and the dye. H-bonding occurs easily in the non-aqua method. In the case of its dry dyeing (in the absence of water) H-bond formation is expected.
4) Covalent bond:
Covalent bonds are highly stable in most organic compounds. If the covalent bond of the fiber molecule with the dye molecule gets stuck in the dyed fiber, the fastness quality of the product will increase. In the case of several reactive dyes, it has been possible to increase the fastness quality by this covalent bond.
