Cationization of cotton is an
electro kinetic phenomena (
zeta potential
Zeta potential is the electrical potential at the slipping plane. This plane is the interface which separates mobile fluid from fluid that remains attached to the surface.is a scientific term for Electrokinetic phenomena, electrokinetic Electric ...
and electro kinetic) for
surface
A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is ...
charge of
cotton
Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...
. The cotton surface is charged with negative
ions. Cationization alters the characterization of the surface of the cotton which allows salt free
dyeing
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular ...
and improves the dye ability of cotton. The process involves the chemical reaction of cationic reactive agents with cellulose.
Etymology
A cation (+) (/ˈkætˌaɪ.ən/), from the Greek word κάτω (káto), meaning "down", is an ion with fewer electrons than protons, giving it a positive charge. The suffixes for cationic groups discern between 'ylium' for cations created by the loss of a hydride ion and 'ium' for cations formed by addition of a Hydron.
Methods of cationization
Cationization involves the modification of cellulosic macromolecules with positively charged sites with chemical reaction of cationic reactive agents for example with
Quaternary ammonium cation
In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure , where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium ion () and the primary, secondary, ...
or using (3-chloro-2-hydroxylpropyl) trimethyl-ammonium chloride (CHPTAC).
Advantages
Cotton possesses a negative surface charge, while reactive and direct dyes also carry a negative charge. The like charges repel each other, and the addition of salt aids in dyeing by generating a positive charge on the cotton surface. The industry has predominantly used reactive dyes to color knitted cotton goods. The treatment of
salt
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...
-laden, colored effluent generated by the dyeing process is one of the industry's primary concerns. Cotton cationization is one of the most effective solutions to the aforementioned problem.
Cationization of cotton enables salt free dyeing and enhances the dyeability of the substrate with anionic dyes such as
reactive dyes and
direct dye
A substantive dye or direct dye is a dye that adheres to its substrate, typically a textile, by non-ionic forces.
Overview
The amount of this attraction is known as "substantivity": the higher the substantivity the greater the attraction of the ...
s. Water and salt consumption are one of the
major
Major most commonly refers to:
* Major (rank), a military rank
* Academic major, an academic discipline to which an undergraduate student formally commits
* People named Major, including given names, surnames, nicknames
* Major and minor in musi ...
problems in the dyeing especially cotton which leads to substantial environmental impact with extra time and cost. Secondly washing off the residual salt is also important for washing fastness properties, which needs more washing baths. Cationization of cotton reduces the
effluent
Effluent is wastewater from sewers or industrial outfalls that flows directly into surface waters, either untreated or after being treated at a facility. The term has slightly different meanings in certain contexts, and may contain various pol ...
, TDS load and water consumption in comparison to the conventional dyeing processes.
See also
*
Quaternary ammonium cation
In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure , where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium ion () and the primary, secondary, ...
References
{{reflist
External links
* https://link.springer.com/article/10.1007/s10098-017-1425-y
Cotton
Textile chemistry
Properties of textiles