Bleaching effect

If lighter colors than these are desired it is necessary to decolorize all the melanin in the hair in a preliminary step, and then add color back to the desired depth in a second treatment. This is known as a double-process treatment. The decolorization step consists of treating the hair with an alkaline mixture of persulfate salts and peroxide. The persulfate is added to the peroxide as a dry powder immediately before applying to the hair. Although the persulfate salts alone do not have any bleaching effect, the persulfate—peroxide mixture can remove all the melanin in the hair. Dark brown or darker hair can be lightened to a light blonde shade in about an hour. 

Bleaches of the simple ammoniacal peroxide type give limited lightening, which can be increased with bleach accelerators or boosters, including one or more per salts such as ammonium, potassium, or sodium persulfate or their combinations. These salts, which are susceptible to decomposition in aqueous solution, are packaged as dry powders and added just before use. In the absence of hydrogen peroxide, however, persulfates do not have any bleaching effect (41). 

The organotin maleate and maleate half-ester derivatives also exhibit this bleaching effect reportedly by a Diels-Alder addition reaction (18). The reaction is specific to the organotin maleates other organotin carboxylates containing normal dieneopltiles fail to produce similar results (19). 

Sodium carbonate peroxide breaks down into sodium carbonate and hydrogen peroxide. The hydrogen peroxide acts as a bleach and as an antimicrobial agent. The high alkalinity of the sodium carbonate boosts the bleaching effect of hydrogen peroxide. 

Yeast bread (37) 5-20% raw or cooked pea flour Decreased volume Bleaching effect with raw pea flour Lower acceptability above 15%... 

Peracetic acid or its anion, produced in situ from A, A, A, A -tetraacetylethylenediamine, in the presence of hydrogen peroxide, in slightly alkaline solution (equation 14), is an effective bleaching agent used in pulp manufacture and laundering. Household washing solution formulations contain perborate and activators that produce peracetic acid of bleaching effect . ... 

Novo Nordisk has also introduced another application of the laccase formulation, namely for stonewashing in combination with cellulase. It enhances the abrasion effect. In this case, a lower dose of the enzyme/mediator slurry is sufficient. Low doses have a mild bleaching effect though the end-result doesn t look like bleaching. Instead the denim looks as if it has been subject to more abrasion. Cellulases can give a stonewashed look to jeans but they have certain limitations when used on their own. If denim finishers want a highly abraded effect, they usually prefer a combination of cellulases and stones to obtain the desired level of abrasion. With the laccase slurry stones are no longer needed. 

Chlorine Water and Its Properties. 1. Saturate 5-10 ml of distilled water with chlorine. Note the colour and odour (carefullyl) of the solution obtained. What substances are present in chlorine water Write the equation of the reaction and its equilibrium constant. Test how the obtained chlorine water affects an indigo solution and coloured fabric. What is observed What substance has a bleaching effect ... 

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