Views: 3 Author: Site Editor Publish Time: 2019-06-28 Origin: Site
Mediators are regenerated iron complexes with gluconic acid as ligands. These mediators are very expensive and not fully harmless from a toxicological point of view. After the reduction and prior to the coloration process the mediator has to be detached from the soluble leuco dye by ultrafiltration.
Electrocatalytic hydrogenation: Electrocatalytic hydrogenation process is very promising for our textile industries. It is also friendly for ecological aspects. Electrochemical hydrogenation is a process which absorbs hydrogen, produce in-situ by electrolysis of water, reacts with absorbed organic substrates (e.g.: vat dye at the electrode surface).
So, Vat dye is called eco- friendly dye. But it is consumed only 17% worldwide. Below the electrocatalytic hydrogenation process is drawn:
Modern techniques
Using nanoparticles: Nanotechnology is essential for textile coloration. Textile fiber composites are basically bound in various types of molecules. After textile coloration, nanoparticles are vibrated and displaced from the actual position. So, dye molecules penetrate the fiber axis and change the phase of the material. Particles which are 1-100 nanometer ranges are called nanoparticles. Nanoparticles are used in two ways in textile coloration. They are:
Nanosized pigment components in textile coloration
The durability of nanocomposites.
Below the pictures of nanoparticles are given