2,2'-Bipyridine Catalyzed Bleaching of Cotton Fibers with Peracetic Acid Part III: Effect of Chain Length of Alkyl Sulfate Surfactants

Abstract

Peracetic acid can be catalyzed to bleach cotton fibers at 30°C by incorporating 2,2'-bipyridine and an alkyl sulfate surfactant in the bleach solution. The 2,2'-bipyridine is sorbed from solution and forms the tris-2,2'-bipyridine ferrous ion trischelate with ferrous ions in the fibers, and it is the trischelate that catalyzes bleaching. Alkyl sulfate surfactants reduce the rate of decomposition of the peracid by forming an association compound with the trischelate. We have investigated the effect of the chain length of alkyl sulfate surfactants on the interaction of the surfactant with the trischelate using sodium octyl, decyl, dodecyl, and tetradecyl sulfate. We report the effect on the rate of decomposition of peracetic acid in the presence of the trischelate, the visible and ultraviolet spectra of the trischelate, and bleaching of cotton. The results indicate that interaction of the surfactant molecules with the trischelate is hydrophobic in nature.