Oxidation of dyes by manganese tetraphenyl porphyrin activated peroxy bleach
- 32 Downloads
The oxidation of a number of dyes in predominantly aqueous systems by tetraphenylporphyrinato manganese(III) imidazole, MnTPP(Im), activated peroxy bleach has been studied in the context of application in detergent systems. Dyes with an olefinic linkage in the chromophoric group are readily oxidized by perborate even in the absence of the activator. On the other hand, dyes with an azo linkage are resistant to oxidation and are bleached only to a limited extent (25%) even by MnTPP(Im) activated perborate. In the presence of a surfactant, alkylbenzene sulphonate, bleaching is further inhibited by micellar solubilization of the dyes. Sulphonation of MnTPP(Im) only marginally improves the bleaching efficiency in presence of the surfactant. MnTPP(Im) is also destroyed by perborate in the absence of the substrate. In view of these limitations, the metalloporphyrin activated peroxy bleach system is not promising for application in detergent systems. Attempts have also been made to explain the difference in the behaviour of different substrates on structural consideration.
KeywordsBleaching oxidation dyes perborate Mn-porphyrin alkylbenzene sulphonate micellar effects
Unable to display preview. Download preview PDF.
- Coon M J and White R E 1980Metal ion activation of dioxygen (ed.) T G Spiro (New York: Wiley) pp. 23–123Google Scholar
- Depoorter B and Meuneir B 1985Nouv. J. Chim. 9 393Google Scholar
- Groves J T and Haushalter R C 1981J. Chem. Soc. Chem. Commun. 1165Google Scholar
- Mackay R A 1987Non-ionic surfactants physical chemistry: Surfactant Science Series, Vol. 7 (ed) M J Schick (New York: Marcel Dekker) ch. 7, pp. 297–368Google Scholar
- Poulos T L, Finzel B C, Gonsalves I C, Wagner G C and Krant J 1985J. Biol. Chem. 260 16122Google Scholar
- Razenberg J A S J, Nolte R J M and Drenth W 1986J. Chem. Soc., Chem. Commun 277Google Scholar
- Renaud J P, Battioni P, Bartoli J F and Mansuy D 1985J. Chem. Soc., Chem. Commun. 888Google Scholar
- Schardt B C, Hollander F J and Hill C L 1982J. Am. Chem. Soc. 109 3812Google Scholar