Chemistry of Stabilizers

Hydrogen Peroxide Bleach Stabilizer

Stabilizers must be added to the bleach solution to control the decomposition of hydrogen peroxide. Stabilizers function by providing buffering action to control the pH at the optimum level and to complex with trace metals which catalyze the degradation of the fibres. Stabilizers include sodium silicate, organic compounds and phosphates.
The addition of alcohol, glycerin or berbituric acid also stabilize hydrogen peroxide. Hydrogen peroxide also decomposes in the presence of finely divided heavy metals such as copper, iron, manganese, nickel, chromium etc. or their oxides with liberation of oxygen.

2H₂0₂ →2H₂0 + O₂

Sequestering Agents

The sequestering agents bind polyvalent cations such as calcium and magnesium in water and in fibres, thus preventing the precipitation of soaps. If polyvalent ions are present, insoluble soaps may form, settle on the fabric and produce resist spots.
There are four major types of sequestering agents to choose from: inorganic polyphosphates, aminocarboxylic acids, organophosphonic acids, and hydroxycarboxylic acids. The inorganic polyphosphates such as sodium tripolyphosphate and sodium hexametaphosphate are probably the best overall in that in addition to sequestering most metals, they also aid in cleansing the fibres. They may, however, hydrolyse at high temperature and lose their effectiveness.
The aminocarboxylic acid types such as ethylenediaminetetraacetic acid (EDTA) are very good in that they sequester most metal ions and are very stable under alkaline conditions. They are the most used types. The organophosphonic acid types such as ethylenediaminetetra (methylene phosphonic acid) are also very effective but comparatively expensive.
Oxalates and hydroxycarboxylic acids (citrates, etc.) are excellent for sequestering iron but not effective for calcium and magnesium. In order to quickly and effectively bring the chemicals to the textile material, i.e. to improve their wettability and to ensure that the fibrous impurities will be removed as far as possible, it is necessary to add surfactants with good wetting and washing/emulsifying properties.
A surfactant of optimal versatility to be used for preparation, and in particular for the scouring and bleaching processes, ought to meet the following requirements.

Emulsifiers

The sodium salt of carboxymethyl cellulose (CMC) is commonly used as a stabilizer or an emulsifier. Emulsifier is used to stabilize emulsion. One type of emulsifiers, Polymeric emulsifiers, are adaptable to a variety of emulsion preparation methods. Polymeric emulsifiers are water insoluble polymers that readily anchor at the oil-water interface independent of oil type. Emulsions, being liquids, do not exhibit a static internal structure. The droplets dispersed in the liquid matrix (called the "dispersion medium") are usually assumed to be statistically distributed.
Two liquids can form different types of emulsions. As an example, oil and water can form, firstly, an oil-in-water emulsion, where the oil is the dispersed phase, and water is the dispersion medium. Secondly, they can form a water-in-oil emulsion, where water is the dispersed phase and oil is the external phase. Multiple emulsions are also possible, including a "water-in-oil-in-water" emulsion and an "oil-in-water-in-oil" emulsion. In all types of emulsions, emulsifier is responsible for stabilizing the dispersed molecules of liquid in another medium.