Question 23 (Textile Engineering & Fibre Science)
A typical curve between equilibrium dye uptake and dyeing temperature goes through a maximum. After the maximum, the dye uptake decrease because
|(A)||Kinetic energy increases rapidly|
|(B)||Pressure in the dye bath increase|
|(C)||Saturation value is reached|
|(D)||Dyeing is an exothermic process|
Answer / Solution
Frequently Asked Questions | FAQs
Is dyeing endothermic or exothermic?
The process of dyeing can be either exothermic or endothermic, depending on the type of dye and the specific conditions of the dyeing process.
In general, the dissolution of dye molecules in water is an endothermic process, meaning that it requires heat to take place. This is because the dye molecules need to absorb energy to break their intermolecular bonds and become solvated in the water.
However, the subsequent reaction between the dye molecules and the fibers can be exothermic or endothermic, depending on the type of dye and the specific conditions of the dyeing process. Reactive dyes, for example, form covalent bonds with the fibers, which releases heat and is an exothermic process. Acid dyes, on the other hand, form electrostatic interactions with the fibers, which is an endothermic process that requires heat.
The temperature and other conditions of the dyeing process, such as pH and concentration of the dye, can also affect whether the process is exothermic or endothermic. In general, the dyeing process requires careful control of these factors to ensure that the dye molecules are able to bond with the fibers and produce the desired color without damaging the fabric.