The Effect of Wool on the Photolysis of a Model Stilbene Fluorescent Brightener

Abstract

The effect of suspended wool on the photodecomposition of a model fluorescent brightener, disodium 4,4'-diacetamidostilbene-2,2-disulfonate in aqueous solutions has been studied. Low concentrations of suspended wool increase the rate of brightener photodecomposition, whereas higher wool concentrations retard the rate of brightener decomposition. Photo-oxidation of the brightener in solution or on wool substrate gives the same major photocleavage product, sodium 5-acetamido-2-formylbenxenesutfonale.

Fluorescent Whitening Agents

“…Thus, not only the types, but also the proportions, of products obtained when fabrics containing I are irradiated parallel those obtained from fabrics treated with III [3], demonstrating that there is no fundamental difference in the mode of photodecomposition of acylamino-and triazinylamino-stilbenes. Seiber and Needles [5] have studied the effect of finely-divided wool on the photodecomposition of aqueous solutions of I by measuring the decrease in absorbance at 330 nm (near the ÀIIl8X of trans-I), which they inferred was a measure of the II produced. However, our results suggest that the system is far too complex to be followed by spectroscopy alone.…”

Environmental impact on the light and perspiration stability of triazinylstilbene fluorescent brighteners on cotton fabrics

“…The light-fastness of TFBs on protein fabrics has been investigated widely and intensively [10][11][12][13][14][15]. The TFBs were considered to accelerate the photo-oxidation of the wool and silk by impacting on the photodecomposition of the histidyl and tryptophyl residues of the substances [12,13].…”

“…The TFBs were considered to accelerate the photo-oxidation of the wool and silk by impacting on the photodecomposition of the histidyl and tryptophyl residues of the substances [12,13]. Conversely, the light stability of TFBs was also influenced by the protein substance [14,15]. However, the current investigations on the light stability of TFBs on cellulose fibers are insufficiently thorough.…”

Light and perspiration stability of triazinylstilbene fluorescent brighteners on cotton fabrics

“…2,[13][14][15][16][17][18] In addition, the relationship between the TFBs and the components in protein fabrics after exposure to light has been investigated. [19][20][21][22][23] The TFBs were considered to accelerate the photooxidation of the wool and silk by impacting on the photodecomposition of the histidyl and tryptophyl residues of the substances. 21,22 On the other hand, the protein substance can also influence the photo-yellowing of the stilbene brighteners.…”

“…The effect of suspended wool on the photodecomposition of the stilbene brightener in aqueous solution has been investigated by Seiber and Needles, 23 and the concentration of suspended wool was proved to affect the rate of brightener decomposition. Furthermore, the light stability and the whitening ability of stilbene fluorescent brighteners are influenced by many factors, such as the irradiation wavelength, the inorganic and organic cations, 11 the property of the fiber matrix, 2,[19][20][21][22][23] the polarity of the solvent, [24][25][26] the nature of the substituents 27,28 and the pH. 29 Nowadays, with the steady improvement of garment requirements, the light and perspiration stability of textiles, especially for cotton fabric used in summer, has gradually attracted consumer attention.…”