Interaction of vinylsulphone reactive dyes with cellulosic fabrics. Part 1 — dyeing mechanism, fibre characterisation and effects of alkaline electrolytes

Abstract

Two vinylsulphone dyes were studied by an HPLC technique under alkaline conditions in order to evaluate their various chemical forms. Fabrics made from viscose fibres were dyed under controlled conditions, varying the nature and the quantity of electrolyte used. It was found that sodium chloride is the most efficient salt for a short dyeing times (20 min) while lithium chloride yields higher dye uptake over more prolonged dyeing processes (60 min). The effect of the electrolytes on dye uptake was found to be related to the radius of the solvated cation.

Hydrolyzed reactive dyes. Part 1: Analyses via fast atom bombardment and electrospray mass spectrometry

“…9. The dichlorotriazine form of the dye (9) has m/z 637.42, the monohydrolyzed product (10) has m/z 618.97, and the fully hydrolyzed product (11) has m/z 600.53. The negative ion FAB spectrum of the hydrolyzed and residual dyes did not contain a peak above m/z 618.…”

“…In addition, while the nature of hydrolyzed dyes is widely accepted, direct analytical evidence for their structures has not been published. Interestingly, in related studies HPLC has been used to separate and quantify hydrolyzed dyes [11,12]; however, in those cases, retention times were employed as a basis for confirming the presence of hydrolyzed reactive dye. In the present study, the commercial and hydrolyzed forms of six reactive dyes were analyzed using negative ion FAB and ES mass spectrometry, the structures of which are shown in Fig.…”

Decolourisation of dyes and dyehouse effluent in a bubble‐column reactor by heterogeneous catalytic ozonation

“…The dyestuffs used are listed in Table 1 with their chemical structures, which were found in the Colour Index and the literature 22, 23. Hydrated alumina [Al(OH) 3 ], silica (SiO 2 ) and ferric nitrate [Fe(NO 3 ) 3 ] were supplied by Aldrich Chemicals (Poole, UK).…”

Decolourisation of dyes and dyehouse effluent in a bubble‐column reactor by ozonation in the presence of H2O2, KMnO4 or Ferral

“…Various materials were used to study the decolourisation behaviour of aqueous solutions of dyes and dyehouse effluents by ozonation in the presence of H 2 O 2 , KMnO 4 or Ferral. The dyestuffs used are listed in Table 1, including their structures, which were taken from the Colour Index and the literature 22, 23…”