What is Oxidising Agent?
An oxidising agent is a reactant that removes electrons from other reactants during a redox reaction. We can also say that any chemical substance that has a tendency to accept electrons and thereby undergoing reduction themselves is known as an oxidising agent. An oxidizing agent is also referred to as an oxidizer or an oxidant. Oxygen is the prime example of an oxidising agents. Halogens (such as chlorine and fluorine), potassium nitrate, nitric acid and hydrogen peroxide (H2O2) are also important oxidizing agents.
Oxidizing agents are mainly used for bleaching in textile wet processing. Oxidising agents are used for desizing also have bleaching actions on cellulose. Hence, partial bleaching occurs during desizing. Oxidising agents are often strong chemicals and need to be handled with care. The assay of these agents is almost always based on the redox titration. In a redox reaction, an oxidising agent (oxidant) is reduced (it gains electrons).
Uses / Applications of Oxidising Agents in Textile Wet Processing:
Desizing is the process or removing the starch or size the covering the warp yarn using enzyme. Oxidising agent, or other chemicals. Lastly, is oxidative desizing method. This method using hydrogen peroxide and persulphate, which will degrade the starch with serious attack.
Though the use of oxidants for desizing of cotton fabric is widely accepted but their large scale industrial application is yet to be exploited. The most important aspects of oxidising agents are that they can be applicable to wide range of fabrics, the size content of which is often not known. The first oxidative desizing agent initially suggested is hydrogen peroxide.
The main limitations of oxidative desizing agents are increased pollution load, fiber damage and inability to recover and re-use water soluble sizes. Oxidative desizing agents require precise control on process parameters. Metals catalyse the action of oxidising agents and the desizing liquor should not be in contact with any metal fittings.
2) Oxidized Starch:
The starch derivatives made by oxidative processes find limited use in textile sizing because they are more expensive to produce as compared to the other starch modifications which can give essentially similar properties to high solids/low viscosity cooks. Instead of using acid to reduce the starch chain length, sodium hypochlorite, an oxidising agent, is employed.
Cotton being a vegetable fiber will be bleached using an oxidising agent. Bleaching is a process of destruction of natural coloring matter to produce white fabric band be accomplished with a minimum damage to the cloth being bleached. Cotton being a vegetable fiber will be bleached using an oxidising agent, such as dilute sodium hydrochloride or dilute hydrogen peroxide. If the fabric is to be dyed a deep shade, then lower levels of bleaching are acceptable.
Oxidizing agents are also vital used in many biological processes such as metabolism and photosynthesis. It is also used in purification of water.
You may also like:
- Application of Enzymes in Textile Processing
- Bleaching Process in Textile: Its Purposes and Chemical Requirements
- List of Chemicals and Auxiliaries Used in Textile Wet Processing
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.